Z28_Demon

All,

I have a quick question...can you still bleed your own brakes if you have TCS (Traction Control) in your car? I read on one of the posts where someone was removing the engine (which I have to do) from underneath and you have to disconnect the two front brake lines. Ok, no problem. However, then they said that when they put the K-member/engine back in and tried the bleed the brakes, they couldn't do it because they had the factory TCS installed on their car. They said that only a dealer can do it.

Is this true? If so, then I have no choice but to pull my engine from the top because I think it is stupid if I have to tow my car to the dealer afterwards and pay them a ton of money just to bleed the brakes when I have done it on other cars for years. Then again, I haven't done it on any car with traction control either. So, I don't know if there truly is something weird or what.

Plus, can you use, again with the TCS installed, those vacuum pumps to help you bleed the brakes? I don't have one, but was considering getting one if I was going to remove my brake lines, but now I don't know considering what I read here on an older thread.

Any info and help would be appreciated.

Thanks,
Mat

mikedamageinc

iTrader: (49)

TCS on these cars has nothing to do with brakes, ABS does. If you just open it at the caliper, it's not hard to bleed the air but if the entire system is opened like you said with the k member, it can be tricky to get all the air out. If you have access to a scanII then it should be easy but if not, bleed like normal, drive it and brake hard to activate ABS a few times and bleed again. Repeat until you get a firm pedal.

Z28_Demon

Mike - Sorry, thank you for the correction. Duhhh...I meant ABS and I'm sure that is what the other person said. I don't know why TCS was on my brain. Makes total sense.

I really wish I had a Tech II scan tool, would make a ton of things much easier. LOL But at least if I know there is possibly a way to bleed the system, then I'll be okay to try and bleed it. Plus, as you mentioned, I'm guessing if I leave the ABS "block" alone and only remove calipers to paint and put those back on, the air in the lines should only be at the end by the caliper, so I should be able to bleed them normally, correct?

Again, thank you for the correction.

mikedamageinc

iTrader: (49)

You should be good if you cap the lines well, they always seem to keep dripping for me. You could always paint them while connected. Clean and prep the calipers, unbolt and wrap a Walmart bag around the rotor and hub bits, put caliper back on a paint it.

Z28_Demon

I was thinking about that. Buying some small vacuum caps and using those to cap off the end of the lines once I disconnect the calipers. Figured that might help.

But, as you mentioned, most just take and put plastic bags taped around the area and shoot the paint around them. I'm considering doing that, but I'm also considering a powder coating gun and kit. If I get that, then I'll just want to powder coat them instead, which means fully taking them off and such. But I do appreciate the tips.

I'm actually more concerned with me removing the lines from the ABS block if I decide to try and drop the engine/trans down under the car instead of using a cherry picker to pull it up and out. Then again, I haven't looked at the setup. I'm wondering if it is possible to pull the lines off the front calipers, cap them off and then remove the sub assy/K-member with the engine and trans out below? This way hopefully no air gets into the ABS block/pump? But again, I don't know how the front brake lines are routed. Might be no way to disconnect them from the K-member when dropping them down, but if there is, I think I'd rather disconnect them at the calipers and use caps or some way to stop them from dripping and getting air into the lines. Plus, hopefully, if I cap it off, that would stop air from creeping up the line and into the ABS pump/block.

Wishful thoughts...I'm sure someone else here would have done the same thing if possible. I just have never removed the engine from below before, but I really would like to get my engine out so I can paint it and truly clean up and repaint my engine bay. Otherwise, I would just pull the heads and cam (when I'm ready) and replace them.

Spartan7

iTrader: (7)

Incorrect, TCS absolutely does have something to do with the brakes. Look at any of these cars that have TCS/ASR equipped, and you'll see an additional brake line running to the rear of the car, one for each caliper. ABS only has just one line for both wheels. The ABS block will have additional valves in it (except LT1 versions, they have an entirely additional block mounted underneath) to modulate each rear wheel individually.

The GM manual specifies needing a Tech II for bleeding cars equipped with traction control, but you can still get away with bleeding like normal, as long as you don't let the ABS block go completely dry.

eb110americana

iTrader: (4)

I have a '98 with traction control. (Traction control cars have 4-channel ABS Vs. 3-channel ABS on cars without it.) I did exactly what the OP suggested: I disconnected the 2 brake lines at the ABS block and dropped the engine from below. You will not be able to lower the motor without doing this, as the lines run across the K-member, so they would be in the way of the engine as it was going down. While things were out of the car, I removed the rear axle and capped the lines as best I could just ahead of the axle. I also replaced all the rubber lines with braided metal lines, bench bled a new master cylinder, put in a new booster, and installed a set of 14" Wilwood 6-piston front brakes. I was able to bleed it pretty easily when I put everything back together, and the car is easily drivable, so you will not have to tow your car anywhere. That said, there is still air trapped in the ABS block, and the brakes, which should be quite firm with all the modifications, are on the spongy side. It is still no problem to stop abruptly, it just requires more pressure to do so. I need to take my car to a brake shop and have them cycle the ABS block for me to bleed the last of the air out. I would not let that stop you from dropping the engine out the bottom though. That was one of the easiest parts of my build--and I did it by myself in the driveway.

mikedamageinc

iTrader: (49)

You are talking about the difference between 3 and 4 channel abs, still nothing to do with ASR, which is what these cars have, commonly called traction control but it's really not. It is acceleration slip reduction. Look at the module, it only intercepts throttle cable. ABS only triggers when wheels aren't turning the same while brake pedal pushed, they will not grab like modern traction control.

Spartan7

iTrader: (7)

It's called TCS (traction control) on Pontiacs. It IS a traction control system, it controls loss of TRACTION. And it's more than just throttle control. Traction control on 4th gen F-bodies controls the throttle, ABS modulation to individual rear wheels, AND spark retard. 4 channel IS traction control, i.e. the ABS can control all 4 wheels independently. Comparing it to modern traction control is ridiculous, these cars are 20 years old. Argue with GM, they named and designed it.

Straight out of a 99 F-body GM manual, page 5-265:
"Traction control will not have any effect on the operation of the vehicle until the control module detects one or both of the rear wheels rotating faster than the front wheels. At this time the Electronic Brake and Traction Control Module (EBTCM) will request the Powertrain Control Module (PCM) to retard timing. If the EBTCM continues to detect the rear wheel are rotating faster than the front it will request the ASM to reduce the throttle angle. The last measure taken to control the rear wheel is for the EBTCM to apply the rear brakes, thus reducing torque to the rear wheels. Once the rear wheels begin to rotate at the same speed as the front wheels, the system will return full control to the driver."

mintws6

Buy a cheap vacuum brake bleeder and send it!

Z28_Demon

Thats what I was hoping to do but if the ABS block needs to be opened by electronic control to allow all the air out then even a vacuum brake bleeder won’t work. My guess anyway. But if the brakes are bleedable enough to be solid to drive to a shop to have them finish off the bleed, then I could live with that. That isn’t too bad, even if I don’t want to spend the extra money on it. But it is better than having to tow it somewhere. 👍🏻

Z28 6spd

iTrader: (3)

This is definitely the way to go on any vehicle, especially late models with ABS/traction control. I bought a vacuum bleeder years ago and it's one of the best tools I ever bought. I've done many vehicles old and new with it, working by myself. No need for someone to be pumping and holding the pedal. Vacuum bled after changing every brake line on my 2006 Silverado and had zero issues with ABS or trapped air.

Z28_Demon

Cool...sounds like when I'm going to do this I'll need to grab a vacuum bleeder. Sounds worth it. Even with help, it's a pain in the butt to have to yell to someone from under the car to press and hold. LOL And then they don't and it sucks air in and after you are done swearing, you have to explain it to them again and do it all over. LOL!!!! :-D

mikedamageinc

iTrader: (49)

Hmm, interesting. I removed my ASR module and I drive mine hard and never have felt any intervention.

Either way that applies to the drive mode, nothing to do with bleeding of the system. I will add that I heard a long time ago to to turn the key to on (not start) for ten seconds, turn off then on again for ten seconds, off, then the abs block is at the top of it's cycle or something like that and then it's ready to bleed.

xny1989

iTrader: (1)

When I replaced my brake lines after one of them burst on me (lucky I was able to get the car to stop), I used a motive brake bleeder - it was a little messy but I had no problem getting all the air out of the block. For the uninitiated, the Motive bleeder attaches to the brake master cylinder and pressurizes the brake system. All you need do is bleed the brakes like you normally do as long as you have brake fluid in the Motive reservoir. Also a great way to flush old brake fluid out.

Z28_Demon

Hmmm...I wonder if something like that is listed in the service manual? I might have to check the brake or ABS section to see if it mentions something like that. Would make it a heck of a lot easier if there was a "trick" like that to open up the ABS block for bleeding.

Z28_Demon

Interesting. I've never seen this type before. But makes sense. I'm guessing it pressurizes the system and sucks the new fluid out of the bottle with the handle on it? No offense to Motive, but their website sucks. LOL I looked at the Domestic GM bleeder and all it does is tell you what caps it includes. It doesn't say anywhere how to use it or gives any information on it. LOL! Kinda odd for a manufacturer. :-/

Anyway, I appreciate the info. Just one more possibility to use and it doesn't need an air line either.

xny1989

iTrader: (1)

Exactly - kinda like a pressurized garden sprayer. The "trick" is to get the part that replaces the master cylinder cap to seal properly. Once done, all you need do is open each brake bleeder, in the proper sequence to get out the air. Just need to ensure that the tank has enough replacement brake fluid and doesn't run dry.

Z28_Demon

Just for the point of being able to do it myself it is probably worth the money. I think Summit had the lowest price when I googled it at like $65 or something. That is for the "black label" GM one. It has the aluminum cap with the different sized gaskets. The good thing is, it will work on my wife's 2012 Mustang as well. So, I wouldn't have to buy a different $40 cap and line for that car alone. Otherwise I'm paying an extra $10 now for that version or another $40 later just for a different cap and line to connect. Best just to shell it out now. LOL Hopefully that means I won't need another one after just getting this one.

gusser

"Interesting. I've never seen this type before. But makes sense. I'm guessing it pressurizes the system and sucks the new fluid out of the bottle with the handle on it?"

Yes, it pressurizes the system (I have one but haven't used it in a long time.. will have to find it again) but it doesn't "suck" the fluid out as much as it "pushes" the old fluid out through the bleeders on the calipers. The can the handle is attached holds fresh brake fluid, which it injects through the master cylinder. This replenishes the fluid your pushing out. As another poster said, be sure not to run out of brake fluid in the can or you'll inject air into the system.

Mine worked quite well the last time I used it, which was on my '71 A-body, may she rest in piece. My soon to be delivered Firehawk probably hasn't had the brake fluid done in at least a decade due to storage and minimal driving by the current owner, so this is one "gotta do" item on my to-do list.

btw: I bought the $40 adapter for my '95 Miata which I got for auto-crossing and it worked fine. A good investment for sure. I am hopeful it works as well on my F-Body.

Hope this helps.