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My 5lug spindles o_O...I’ll need to pull all of the 4 lugs off and get the new replacements in....bTW, they are ordered along with another set of tpms sensors.
Now the question is ...do I want to go through the pain of installing an ABS system in this nonABS Cobalt and then the rear disks and rear axle assembly.
As far as brand or rotors etc. I’ll find out Saturday about 2:00pm
 

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Discussion Starter · #22 ·
If you have been driving as long as I have- and I think you have- who needs ABS? You pump the pedal when you feel the tires skid. ABS is for drivers who can't or won't understand that. ABS has it's own PCM too right? That's a LOT of unnecessary work IMHO.
 

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ABS has it's own PCM too right? That's a LOT of unnecessary work IMHO.
Yes and no and yes...
The ABS pump has a processor built in as part of the pump unit receiving signals from the wheel sensors, it speaks with / to the BCM.
I do not believe there is another separate box.
And yes, I pump the brakes
And as for a LOT of unnecessary..... I think I agree.
I have not found all of the schematics. Wiring diagrams, and all of the hardware. But it should just bolt right up on the BC with the 4 new 5 lug hubs and they all come with wheel sensors.
So I have a choice right now. 5 lug drums on the rear and no change to any of the rear hardware except for the wheel bearing/hub. The 5 lug drums will slide right on. Then on the front, new 5 lug hubs and the SS Cobalt 11-5/8” rotors and calipers (JL9 296mm x 26mm frt rotors, vs J41 256mm x 23.69mm front rotors. And 5 lug JM4 9.06" rear drums.)
This way I won’t be forced to cut the disk ears off of the SS rear axel assembly I have.
 

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Discussion Starter · #25 ·
I guess they consolidated the computer stuff over the years. I remember when the ABS pump was seperate from the ABS module. The module being the computer. I have a set of '05 and '08 factory manuals. If you need wiring diagrams I can send you whatever pages you may need. Speaking of the tpms sensors, what is the difference of "programmable" and "non-programmable"? Which do our cars use?
 

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If you have a rear disk axle, I'd just go with rear disks - you'll just need the new master cylinder, sans ABS valves, to correct the pressure going back there. The rear axle should be a real quick swap.

My conundrum is whether or not I want to switch from 4 to 5 lug, as I have no interest in changing what wheels I have. They sold them in a 5x110, but I don't think they're made anymore.
 

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I picked up the wheels, brakes, and sway bar. The sway bar is indeed a SS front sway bar still with the GM part sticker on it. The wheels are 18” with Toyo proxes4plus 215/45R 18s.
The rotors have only a few thousands of wear ...measured by finger...a brake lath will give the final results. The calipers are complete to and including the banjo bolts and still have the GM LH and RH paper stickers on them. And was offered another complete SS rear end...with shocks!
 

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Discussion Starter · #28 ·
MP81 isn't the combination valve separate from the master cylinder? Or did they incorporate that in too? I haven't had to play with any of those so I don't know what they used on Cobalts. Normally a 4 wheel disc system needs a different master cylinder, limiting valve and proportioning valve (combination valve), and sometimes even a different power booster.
 

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Discussion Starter · #29 ·
So I spoke with a friend who works in a tire shop. They use Autel MX sensors exclusively. They use the Autel tool to set them up and get the car in sync with the sensors. He said they are good for just about every car on the road. The old factory sensors are not worth tracking down and most are obsolete anyway. Best of all the Autel sensors have very good batteries and will easily last the life of the tires. Snooping online I see them going for around $30 each and they are compatible with both 315hz and 433hz systems. The Autel tool that will talk to the car's computer via a scan tool cable is around $150-200. It will test the battery, show the sensor ID, sync the sensors to the transponder, and re-program if needed. Is it worth it to have that capability? We own four vehicles that have tpms and some are getting old. I might have to step up and upgrade to this new system.
 

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MP81 isn't the combination valve separate from the master cylinder? Or did they incorporate that in too? I haven't had to play with any of those so I don't know what they used on Cobalts. Normally a 4 wheel disc system needs a different master cylinder, limiting valve and proportioning valve (combination valve), and sometimes even a different power booster.
I can't say as I've not really looked at it in-depth. It'll basically all need to be replaced since the pressures are all different for the rear.
 

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Discussion Starter · #31 ·
Yes, the front-to-rear differential is different. No need for a residual pressure valve either. My buddy used an adjustable proportioning valve with his 4 wheel disc Firebird. He tested on a rainy day as he wanted the best possible bias for wet road conditions. This was WAY before ABS. Anyone know how the magnet tool was used to reset tpms sensors? I think that was on much older cars than these. In other news I had my grandson go out and try getting the car into tpms re-learn mode. He turned the ignition ON and pushed the lock/unlock fob buttons at the same time. Nothing happened. I had tried the INFO button and also nothing happened. I may need an OBD2 capable tool to force the car into re-learn mode.
 

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Discussion Starter · #32 ·
Well I got a spanking good deal on an AUTEL TS508 tpms scan tool. What a tool! It identifies the sensors, reports on battery health, can activate sensors without deflating the tires, reprogram sensors, clone the OEM numbers, re-learn positions, clear codes, has a DLC cable to talk to the car's computer, and I immediatly registered and updated it with a USB cable online. I am impressed. What I found out was that all are OEM Schrader sensors and 13 years old. Two are still good and two are dead. Looks like I will be replacing them all just because.
 

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Discussion Starter · #33 ·
I found two Schrader 20153 replacement sensors on Fleabay for a very good price. I will try those and see how this goes. They should be exact replaments and the car should relearn their position easily. If not I will use the AUTEL sensors and do them all at once.
 

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Congrats on the scan tool and the sensors. Might keep looking for another 2 sensors.
13yrs was a good run for a couple of batteries. They could last the next set of tires you moun
 

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Discussion Starter · #35 ·
I plan on testing before I go and dismount any tires. I will place a sensor on the top of each tire that has a dead sensor. Then I will go through the test and re-learn procedure. If I get a reading at each corner I will then dismount and install. Yes, all four will need to be done. And I only want to do this once so- test-test-test. I have a Harbor Break manual tire mount tool that I never expected to get so much use out of. It can break a bead easily and then I can push the sidewall down enough to change out the sensors. I don't want to have to re-mount the tires if I can help it. Since the OEM sensor is also a Schrader with the same part numbers I figure it should be the same exact weight as the originals and not need balancing. I'll know for sure when I open them.
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Ah fudge @ that harbor brake tire tool. I need to dismount 4 ea 215/45R18s to strip, clean and repaint. Then remount & balance. That floor mounted tire biter looks like it would do it but, I don’t think I have enough left in by back pockets to do it without a blister, skinned knuckle, or broken ...
So your a better man than I GungaDin
 

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Discussion Starter · #37 ·
18" tires? No way. My '95 Firebird has 17" Eagle rims and even my tire shop buddy had a hell of a time mounting some 275-40-17 Michelins. That HF tire buster is great for 15" tires with fat sidewalls. Plenty of give on those. The skinny sidewall tires need a real tire machine and a guy that knows his stuff. My buddy pulled out tire tools I had never seen before and still battled those 17" tires on. The HF tool is good at getting the bead broken loose on a stock wheel, then I can swap out the sensors. I have even used an OEM bumper jack and my station wagon to bust a bead just to change a bad valve stem. My grandson volunteers at his college radio station on Fridays so after that I will take his Cobalt for an inspection. I want it done before the weather gets winter nasty. Then I will attempt the sensors. Stay tuned.
 

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Good luck on the inspection. Right now I’m rubbing out the fresh clear coat on the top surfaces, trunk is done, hood 1/2 way sanded to 1200 grit. Roof is waiting.
All this with a fresh coat of U403P (Imperial Blue Metallic). The original color of the BC The 18” are a stock Cobalt wheel....mind you an SS but still stock Cobalt. Something to play with...for this 2008 Cobalt BS.
 

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And for an 18, it isn't all that low profile. I run a 225/40R18 (which is the standard SS/TC size), and it being a Direzza ZII, it has an absurdly stiff sidewall that made it an absolute chore to get onto the wheel.
 

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Discussion Starter · #40 ·
Exactly. The sidewalls just would not flex enough to get on the rim. So bad you thought it was the wrong size. What a battle. I wanted the inspection done in August but the monitors were not ready. Even after doing a drive cycle. I had the battery disconnected a lot because of all the electrical work being done. These inspection guys all say the same thing- drive 100 miles and come back. What it actually needs is the computer wants to see a certain amount of "good cycles" where the cold engine is brought to operating temps, run around, then cooled off with no codes being set. The evap is the hardest to get cleared and in NY you are allowed one monitor to be not ready because of that. If it passes then I tackle the sensors.
 
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