- New BigCoupeGroup stuff:: http://bigcoupegroup.com/archives/30 #
- New BigCoupeGroup stuff:: Checking Out A Car http://bigcoupegroup.com/archives/35 #
- New BigCoupeGroup stuff:: Brake Boost/Master Cylinder Leak http://bigcoupegroup.com/archives/39 #
- New BigCoupeGroup stuff:: EEZIBLEED Pressure Brake Bleeders http://bigcoupegroup.com/archives/42 #
Twitter Updates for 2010-06-09
DIY Brake Bleeder
Attached are 2 articles describing a pressure bleeder you can make at home, assuming you have tools to drill holes in 1/4″ metal and 5/8″ plastic. A vice helps a lot too.
The articles mention a 1/2 gallon tank which is more accurately a 2 liter tank. The cap needed for the fluid reservoir on the car comes with a 500ml jar. Both containers are made of plastic and are sold under the brand name Nalgene. I found them at Erehwon, an outdooroutfitter.
The plastic tubing referred to as 5/16″ OD and 3/8″ ODis vinyl, the 1/4″ OD tubing is PVC. I found all at an ACEhardware store.
The tire stems I found were Camel brand nbr. 30-445 at Track Auto. No one store had 4 of them on the rack at one time. I visited 3 stores. An alternate to 30-445 might be nbr. 30-463. I found this after I built mine.
| Item | Qty | Unit Cost | Extended Cost |
|---|---|---|---|
| Stems/valves | 4 | 2.99 | 11.96 |
| Tubing | See Article | 1.40 | |
| 500m Jar with #3 cap | 1 | 1.90 | |
| 2000ml Jar | 1 | 7.50 | |
| 1 quart Jar | 1 | 3.90 |
====================== Article 1 ============================
I fabricated a pressure (not vacuum) bleeder out of a couple of sturdy plastic tanks (1/2 gal supply, 1 qt waste), tire valves, and hose. The unit fits onto the reservoir, uses 10# of pressure and has none of the leak problems which the vacuum units seem to be plagued with. It is not that expensive (<$20), works well, and looks like it is professionally made. The main tank is from an outdoor outfitter, takes the pressure, and I was able to find a cap at the same store which fit the reservoir (so I didn’t have to buy from the dealer a BMW reservoir cap). I seal it off after bleeding and am ready to go next time. If anyone wants more detailed instructions let me know. Wife and kids no longer have to deal with the up-down routine.
====================== Article 2 ============================
I received a number of inquiries about the brake bleeder and not having a lot of confidence in net graphics I’ll try to describe the setup with words. If it is not clear or if you have questions, just drop a note. If you are hopelessly befuddled by my directions, give me a mailing address and I’ll send you a diagram. Here goes:
PRINCIPLE: Push fluid into the reservoir at pressure to force the old fluid out the caliper nipples rather than suck it out from the nipples. Brake systems are pressure systems and are better able to deal with even this small pressure than a vacuum system which will always suck a little bit of air in at the nipple.
PARTS:
A: 1 each– 1/2 gallon heavy duty (Nalgene) plastic tank. I bought one from Hudson Bay Outfitters, a local dealer of outdoor equipment. They had many different styles and shapes. My criteria were a) a good tight seal on the screw cap, b) very solid construction, and c) a relatively flat surface area on the top where I could mount a metal tire valve. The dimensions of the tank I bought were 8″(h)x6″(w)x3″(d). I think it is most important that it be sturdy and that most of the volume be air rather than fluid so that the pressure remains relatively constant during the bleed, I use Ate Super Blue and put about a half quart in the tank. This tank was the most expensive part ~ $9.50
B: 1 each– 1quart tank into which old fluid is collected. You have probably used a form of this in the past. At the same same outfitter store I got a lighter duty quart jug for this purpose, put another tire valve in the cap, drilled the valve out with a 1/4″ bit, and ran a 5/16″ hose from the caliper nipple over a short section of stiff 1/4″ tubing which goes through the valve and down into the tank. A very small hole drilled into the cap next to the valve will allow air to escape. No more catching fluid in a wine bottle, if this one falls over it is no problem, because for all intents and purposes it is a single piece.
C: 1 each– Nalgene cap to temporarily fit the top of the reservoir in place of the existing one with the sending unit. I found a Nalgene cap about 1 3/4″ in diameter which fit my old 633 perfectly (a tight fit here is essential). This part may take some trial and error and the cap from one reservoir may be different from another.
D: 2 feet of 3/8″ OD x 1/4 ID vinyl hose– to go from A above to the cap C.
E: 2 feet of 5/16″ OD hose to drain the fluid into B.
F: 9″ of stiff 1/4″ OD tubing to fit inside the tank A from the drilled valve down to a corner in the tank (take a look at the pesticide tank in your garage if you can’t visualize this).
G: 4 metal type screw valve stems– I bought them at Track Auto, drilled out three of them as described in B above. The fourth one is mounted in the cap of A above and is used to pressurize the system (in other words don’t drill this one out).
CONSTRUCTION:
Drill out three of the four valves with 1/4″ bit (be careful and use a vise). Drill out all three caps to accept the valves as well as a spot on the shoulder of tank A. Mount undrilled valve in cap of Tank A. Insert 1/4″ stiff tubing into bottom end of one remaining valve and mount valve on shoulder of Tank A. Mount a remaining drilled valve into hole in cap which mounts on reservoir. Put 3/8″ OD hose on the two valve stems just described. Collector tank construction is described above. I have a small electric pump but a hand pump will do. I wouldn’t pressurize above 10 to 15 psi. Larger hoses will improve flow and a stop cock valve allows you to fine tune your setup but is not necessary. A local observer suggested a strap for the reservoir to ensure your reservoir doesn’t decide to lift off, another unnecessary precaution in my experience. You don’t have to do anything while it is bleeding (as usual, one at a time), but you might try applying a bit of pressure to the brake pedal to get things moving.
OPERATION:
Put about a half quart of your favorite fluid into Tank A and tighten lid. Replace cap on reservoir with Cap C and make sure you have a good seal. Pressurize Tank A, look for leaks ( I have never found any) and open your caliper nipples in the traditional fashion. After you are finished, release the pressure in the tank by pushing down on the valve release… then remove the caps. Have fun.
This is not as difficult as it may seem, I just wanted to be as detailed as possible. The directions are lengthy so I decided not to post. But I have gotten about 20 inquiries. Your thoughts?
- Jon Lindsay
jonlindsay@aol.com
New BigCoupeGroup stuff:: EEZI…
New BigCoupeGroup stuff:: EEZIBLEED Pressure Brake Bleeders http://bigcoupegroup.com/archives/42
EEZIBLEED Pressure Brake Bleeders
If you are looking for an inexpensive one person, pressure brake bleeders, John Abbot, who sometimes advertises in the Roundel sells EEZIBLEED for $35.00 deliveredYou can call John at (407) 483-7898. You can also e-mail John for additional information. I have used this system for 3-4 years now and really like it. The only caution is that you will be tempted to over- tighten the bottle’s lid and thus distort the gasket. Tighten it only enough to hold the 15-17 lbs of air.
- Norm Grills
grills@airmail.net
Brake Boost/Master Cylinder Leak
Had the same problem with the hydraulic leak from the brake booster on my ’87 635. The leak is from a failed “O” ring inside the booster. The ring is about 2″ in diameter and goes around the plastic plug in the front of the booster. The screw you feel under the booster is the retaining screw for the plug which, by the way, has a fairly strong spring behind it. Be careful if you take it apart. I took the booster out myself and got a replacement “O” ring from Steve Haygood, the guy who runs the 6 Series Register.
- DREESBACH@cpo.al.wpafb.af.mil
Addendum:
This O-ring is a 3mmX38mm (ID) and can be found at Pep Boys. Don Meis and I have both found them there.
- grills@airmail.net
Repair Library Review
In the past, on BCG and Bimmer.org, I’ve seen a lot of questions about the availability, cost and quality of repair information for our 6ers. Since I seem to have collected a bunch of these references, as I restore my 1987 L6 back to it’s former glory, I thought it would be helpful to provide a brief description, opinion, availability, and cost on each. Not endorsing any particular vendor, just relaying where I purchased the material and some of my thoughts on each. Sort of long but I hope this is helpful for those who are new and/or for those wondering if buying a particular reference will provide the kind of information needed. Maybe Norm can create a FAQ for future reference?
Regards,
Scott
**** BMW Factory Repair Manual ****
Cost: Approx. $135 Purchased from: All BMW Parts / Dealer Marketing Contact: http://allbmwparts.com/bmwpart/ Impressions: A 3″ binder packed with detailed, mostly repair and selected troubleshooting and theory of operation descriptions. Covers 635 and L6/M6 models from ’83 to ’87. Very good photographs and diagrams, although some photos seem to be a bit dark and detail-less. I’ve used this manual countless times when I needed more detail than the Bentley Manual could provide or when I needed another perspective on a problem. Price is high, but considering an $90/hr. rate, it pays for itself in about an hour and a half. If your doing a restoration or a serious DIYer, then this is a manual to own. If your an occasional DIY or put off by the high price then a Bentley Manual is the way to go.
The Table of Contents include the following subjects: Maintenance and General Hints, Warranty, After service Development, Professional Development, Tools and Equipment, Customer Relations, Engine, Engine Electrical, Fuel Systems, Fuel Supply, Cooling Systems, Exhaust Systems, Clutch, Manual Transmission, Automatic Transmission, Gear Shift Mechanism, Drive Shaft, Intermediate and Special Transmission, Front Axle, Brakes, Pedals, Wheels and Tires, Special Suspension Systems, Body, Body Equipment, Seats, Special Roofs, General Electrical, Instruments, Lights, heating and AC, Sound, Cruise, Alarms and Monitors, Remote Control Systems, Vehicle Tools, Safety Restraint Systems, Phone and Navigational Systems, Corrosion Protection and Paint Work.
For some reason, a few of these chapters are removed, especially the first 6 I mentioned above. Not much in the way of electrical details. See the ETM description below. BTW, I believe there is Microfiche available (a lot cheaper) for this but you will need a reader that can read the larger German fiches. Bottom line for me was that it was not very portable and convenient to buy the fiche.
**** Electrical Troubleshooting Manual ****
Cost: Approx. $75 Purchased from: All BMW Parts / Dealer Marketing Contact: http://allbmwparts.com/bmwpart/ Impressions: Invaluable and highly recommended for the serious DIYer. A 1 1/2″ binder full of detailed schematics, connector views and locations, and splice locations. Also includes fuse data and some troubleshooting guides for selected systems. Covers 635, L6 and M6 for a particular model year. Photographs can be a little grainy and narrowly focused (Can’t tell when the part is located – not enough surrounding detail). Fixed many problems with this manual and has paid for itself many times over. Ever wonder how your factory stereo is hooked up? Ever wonder why your switches don’t work? Ever wonder why your heating control doesn’t work. Having problems with your starting system? Take the guess work out of electrical troubleshooting, it’s expensive and time consuming. A great companion/compliment to what ever repair manual you buy.
The Table of Contents include the following subjects: Index (full list of all schematics in the manual), Symbols, Wire size conversion chart, Systematic troubleshooting, Connector views, Power distribution box, Fuse Data, Component location chart, Component location views, Splice Location Views.
**** Bentley BMW 5-Series (E28, 1982-1988) ****
Cost: Approx. $45 Purchased from: Steve Haygood Contact: 706 647 0302 or shaygood@alltel.net Impressions: Probably the most purchased reference manual for the 6 series. Don’t be fooled by the cover referencing the E28. Many systems are the same or similar between the two, making it an affordable and available reference book. Excellent reference containing great combination of diagrams and repair description. It also provides detailed information on general maintenance procedures. While not as comprehensive and detailed as the BMW factory manual, it generally does a better job at describing a repair procedure. It’s very comprehensive and could be the only manual you need for most DIYers, although I would still recommend the Electrical Troubleshooting Manual as a companion.
The Table of Contents include the following subjects: Fundamentals, Lubrication and Maintenance, Engine service and repair, Engine reconditioning, Fuel supply, Fuel injection, Ignition, Battery, Starter and Alternator, Cooling system, Exhaust, Manual transmission and clutch, Automatic transmission, Drive shaft and final drive, Suspension-Front, Suspension-Rear, Steering and Wheel alignment, brakes, body and interior, Heating and AC, and Electrical systems.
The Bentley Manual also covers torque specifications for most repairs. This is something the BMW Factory Manual does not provide.
**** Mobile Traditions Parts CD ****
Cost: Approx. $45 Purchased from: Steve Haygood Contact: 706 647 0302 or shaygood@alltel.net or your local BMW Parts Shop Impressions: Another great reference depicting exploded parts views and part numbers for a wide selection of historic BMW autos and motorcycles. I’ve used this CD countless times to identify parts when purchasing them from my local BMW shop or mail order vendor, identifying how the various assemblies fit together, help in troubleshooting problems. I think the biggest benefit for me with this parts CD is to be able to cross reference parts from other 6 series years/models when looking for used parts. The big question when dealing with this is “Will it fit my year and model?”
Besides the 6 series other vehicle exploded parts views contained on this CD include: Isletta, 1500-2000CS, 1502-2002tii, 2500-3.3Li, 2.5-3.0CSL, E12, E21, E23, E24, E30, and Z1. This is very similar to the software you local BMW parts counter has when you ask him to look up a part, less pricing and availability of course!
The Table of Contents include the following subjects: Engine, Engine Electrical, Fuel Systems, Fuel Supply, Cooling Systems, Exhaust Systems, Clutch, Manual Transmission, Automatic Transmission, Gear Shift Mechanism, Drive Shaft, Intermediate and Special Transmission, Front Axle, Brakes, Pedals, Wheels and Tires, Special Suspension Systems, Body, Body Equipment, Seats, Special Roofs, General Electrical, Instruments, Lights, heating and AC, Sound, Cruise, Alarms and Monitors, Remote Control Systems, Vehicle Tools, Safety Restraint Systems, and Phone and Navigational Systems.
Follows the same Main Group structure that the BMW Factory Manual Covers (sometimes with slightly differnt names for the Main Group).
**** Popular Mechanics Automotive Repair Information ****
Cost: Approx. $ 19 Purchased from: Autozone Contact: http://www.autozone.com/ Impressions: The jury’s still out on this one. I mainly purchased the CD to get access to the TSB’s for my L6. It seems sort of clunky to get around the software and it provides really limited repair information. Graphics are generally poor with some just unreadable. A bit disappointed in the repair and troubleshooting sections to say the least. Again, my reason for purchasing was to gain access to the TSB’s (the entire TSB and not just the titles like you find on the Alldata site). Recommended for TSB’s.
**** Chiltons BMW Coupes and Sedans, 1970 to 1988 ****
Cost: Approx. $30 Purchased from: Barnes and Noble Contact: http://www.barnesandnoble.com/ Impressions: My first reference manual after buying my L6. Couldn’t find a Bentley so I settled for this. Had to get a quick fix in learning about my new project car! Ok in the beginning learning about BMW repairs, but the benefits faded fast. This reference tries to cover too many models over too many years. While there is a lot of similarities between the models, I found that the repair information too light on description for any particular model. My lack of confidence in this book culminated in providing me wrong valve adjustment procedures for my L6. Thanks to BCG and Bentley for getting me back on track! This is a book I rarely use. My money would go toward a E28 Bentley Manual, described above, if I had do it over again.
**** BMW Owner’s Handbook ****
Cost: Approx. $8 Purchased from: Local BMW dealer parts counter Impressions: Buy it! It’s cheap and provides a lot of good information about your OBC, heating and cooling adjustments, seat memory programming, fuse box information, and technical specifications among others.
**** BMW 6 Series Enthusiast’s Companion ****
Cost: $45 Purchased from: Amazon.com Contact: www.amazon.com Impressions: Great non-technical reference book on the 6 series history and development including racing history for the US and Europe, Performance, and production figures and specifications for each year. Also Insider’s tips on 6 series purchase, ownership and restoration. This is the book by Jeremy Walton. Won’t help you fix your leaky PS reservoir but it will give you an appreciation of the 6 Series history. Also contains discussions of the 6ers predecessors like the 2002, M1 and 3.0 CSL/I.
**** Web References ****
Last but not least, all great references are not always on CD or paper! Try WWW.bimmer.org and the Big Coupe Group at http://web2.airmail.net/grills/b_c_g_FAQ/b_c_g_FAQ.html. I use these almost exclusively for my BMW Newsgroup and mail server information sources!!!
- sgoodno@airmail.net
Tool Kit Contents
| 628csi | 630cs | 633csi | 635csi | M635csi | |||
| 1 | Tool box | 1 | 1 | 1 | 1 | 1 | 71 11 1 117 105 |
| 2 | Plug (Male thread. For lid) | 1 | 1 | 1 | 1 | 1 | 71 11 1 117 440 |
| 3 | Threaded plug (Female thread. For lid) | 1 | 1 | 1 | 1 | 1 | 71 11 1 113 291 |
| 4 | Holding strap, gray | 1 | 1 | 1 | 1 | 1 | 71 11 1 116 719Z |
| 4 | Holding strap, black | 1 | 1 | 1 | 1 | 1 | 71 11 1 179 443 |
| 5 | Sound absorber | 1 | 1 | 1 | 1 | 1 | 71 11 1 113 754 |
| 6 | Foam rubber insert – 05/82 | 1 | 1 | 1 | 1 | 71 11 1 114 789 | |
| 6 | Foam rubber insert 05/82 - | 1 | 1 | 1 | 71 11 1 127 421 | ||
| 7 | Body nut ST4.2-1 | 8 | 8 | 8 | 8 | 8 | 07 12 9 925 709 |
| 8 | Fillister head self-tapping screw | ||||||
| ST4.2 X 19 | 4 | 4 | 4 | 4 | 4 | 07 11 9 907 950 | |
| 9 | Tool kit | 1 | 1 | 1 | 1 | 71 11 1 115 329 | |
| 10 | Combination pliers | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 092 |
| 11 | Water pump pliers | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 091 |
| 12 | Open end spanner 8-10 | 1 | 1 | 1 | 1 | 1 | 71 11 1 126 208 |
| 12 | ” ” ” 10-11 | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 078 |
| 12 | ” ” ” 12-13 | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 079 |
| 12 | ” ” ” 17-19 | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 080 |
| 13 | Box end spanner 9-10 | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 081 |
| 13 | ” ” ” 12-13 | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 082 |
| 13 | ” ” ” 17-19 | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 099 |
| 14 | Screwdriver, long, flat tip | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 190 |
| 15 | Screwdriver, short, flat/phillips | 1 | 1 | 1 | 1 | 1 | 71 11 1 179 629 |
| 16 | Spark plug wrench | 1 | 1 | 1 | 1 | 71 11 1 179 745 | |
| 16 | ” ” ” , adjustable | 1 | 71 11 2 225 101 | ||||
| 17 | Socket wrench 10-11 | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 084 |
| 18 | Pin (Spark plug wrench handle) | 1 | 1 | 1 | 1 | 1 | 71 11 1 103 085 |
| Cleaning rag | 1 | 1 | 1 | 1 | 1 | 71 11 1 115 810 | |
| Fuse 5A – 05/82 | X | X | X | X | 61 13 8 760 141 | ||
| ” 8A – 05/82 | X | X | X | X | 61 13 8 760 138 | ||
| 16A – 05/82 | X | X | X | X | 61 13 8 760 140 | ||
| 25A – 05/82 | X | X | X | X | 61 13 8 760 139 | ||
| 7.5A 09/82 - | X | X | X | 61 13 1 370 987 | |||
| 15A 09/82 - | X | X | X | 61 13 1 372 626 | |||
| 25A 09/82 - | X | X | X | 61 13 1 372 627 | |||
| 30A 09/82 - | X | X | X | 61 13 1 372 628 | |||
| Bulb (All 12V) | |||||||
| 4W | X | X | X | X | X | 07 11 9 978 256 | |
| 5W | X | X | X | X | X | 07 11 9 978 227 | |
| 10W | X | X | X | X | X | 07 11 9 978 230 | |
| 21W | X | X | X | X | X | 07 11 9 978 370 | |
| 5W | X | X | X | X | X | 07 11 9 978 340 | |
| 10W | X | X | X | X | X | 07 11 9 978 305 | |
| 55W (Pigtail with spade connector) | X | X | X | X | X | 07 11 9 978 390 | |
| 55W (Spade connector, w/o pigtail) | X | X | X | X | X | 07 11 9 978 390 |
X means quantity greater than 1
Alfred Sutlick <asutlick@adnc.com>
Basic Tips
This reminds me of some other things I do to prevent self-inflicted damage to my cars… If, like Pogo Possum (and me), you “have seen the enemy and he is us”, maybe you’ll find them useful.
First, the general ones:
1. If you’re going to work on your car, schedule the work for a time when you’re alert and unhurried (i.e., NOT the night before a track event).
2. Take careful notes the first time you perform any repair procedure. This is especially useful if you’re not actually REPAIRING something, but just ADJUSTING it… For example, if you’re aligning your car, it’s nice to be able to look at the notes you took last time and see that adding one shim adjusts the camber by “x” degrees, or that one turn of a turnbuckle adjusts the toe by about “x” millimeters.
If you find errors, omissions, or ambiguities in your repair manual, make corrections THERE, in the margins or on a sheet of paper stapled to the appropriate page.
Now some specific ones:
1. Before I do any work on my car, I put the keys in a sealed envelope. This way, if it gets late and I go to sleep halfway through the job, I don’t wake up the next day, grab the keys off the nightstand, and drive to the corner deli with a torsion bar disconnected or something.
2. My dad lives in Denver, Colorado, takes long walks every day, and picks up tools that he finds in the street. He’s amassed about a dozen complete sets of metric and standard sockets, along with a truly impressive array of ratchets, screwdrivers, allen wrenches, punches, etc.
Most are Taiwanese, of course, but he has no shortage of found-on-the-street Snap-On sockets and ratchets, either. If you live in Denver, please keep your tools in a big rollaway cabinet and contimue to “temporarily” leave them on your car’s bumper or engine crossmembers while you’re working… I don’t want my dad’s supply of found tools to dry up.
If you live anywhere else, consider buying one of those cheap plastic tool cases with molded compartments for each of your ratchets, sockets, etc… They don’t look as good as the Snap-On cabinets, but since they provide a place for every tool, it’s easy to tell when there’s a piece still missing.
3. I’ve never left a wrench in the engine compartment, but I DID once manage to disable a car by leaving a rag in there; the rag was sucked into the fan-pulley, it dislodged the alternator belt, and the car died when the battery did: 40 miles from home on my way to Willow Springs.
This will never happen to me again, because I now take shop rags out of the box ten at a time, never one at a time. When it comes time to button the car back up and test-drive it, I count the rags that’re out of the box and make sure the total is a multiple of 10.
4. I’ve seen race cars go out on the track with lug nuts only finger-tight on the wheel studs, loose bodywork, and dangling exhaust brackets. Aside from being potentially dangerous, this sort of thing is very embarrassing… To keep it from happening to you, follow this simple rule: Whenever you put a fastener together (like a lug nut on a wheel stud), even if you KNOW you’re going to be taking it apart again in an hour, TIGHTEN IT FULLY.
Alternately, you can also just keep the fasteners COMPLETELY apart, so long as you make it impossible to overlook the fact that you’ve done so. I accomplish this by putting all loose nuts and bolts in a box on the driver’s seat whenever I take a break from working on the car.
Tools for the absent-minded:
1. If you’re disassembling a large chunk of your car for the first time, a Polaroid camera makes it real easy to document exactly how everything’s supposed to fit together when you reassemble it.
2. Wire-marker labels (just little consecutively-numbered or -lettered labels suitable for wrapping around the ends of electrical wires) are a wondrous thing… If you use them, you’ll never have to worry about, for instance, which of the 25 identical white wires in a 914-4′s disconnected fuel-injector harness goes where.
3. Zip-Loc polyethylene parts bags with “write-on” areas are also real handy… Especially if you spread a repair job over a couple of days, they make it real easy to remember which screws (or whatever) go together.
I buy my parts bags and wire markers (and all SORTS of other tools and hard-to-find little parts) from Small Parts, Inc. You can get their catalog by calling 800 220-4242; they also have a web site at:
http://www.smallparts.com
Andrew Warren – fastfwd@ix.netcom.com