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View Full Version : Car Brakes Question-- Help?



kaneboats
11-12-2010, 12:26 PM
Allright, we are in the off season for most of the country so I don't feel bad throwing this one up. Please ignore this if you don't like car issues, don't want to help or just don't know.

I got my daughter a '95 Saturn SC2 after she wrecked our Mustang. It's a decent little car and was really cheap. I was already dirty from putting a new wheel bearing assembly and front brakes on the wife's truck. So, I decided to look at the spongy brakes on the Saturn. With new front pads in hand I jacked up and pulled the front wheels off. The pads are fine. I decided to bleed all the brakes and inspect the rear drums instead of wasting time putting fronts on it when it really doesn't need them yet. When I went to the right rear and started the process I found a leaky wheel cylinder. I returned the front pads/exchanged for a new wheel cylinder for the rear and replaced the bad one. Got it all back together and adjusted up. The linings are a little worn but not too bad so I didn't bother replacing them either.

So back to the bleeding. Bled the R rear and after about 8 pedal presses by my assitant the fluid was clean and bubble free. Went to the L rear and started the process there. Lots of bubbles. Topped off the master cylinder as we had pushed several ounces of fluid through. Lots of squeaking as air was released when I cracked the bleeder valve. Must have gone through 25 pedal presses-- brand new fluid coming through but still getting air bubbles each time-- some of them pretty big.

The pedal is still spongy but the car will stop. Checked the fronts and no air at all-- bled till clean fluid came out. Still getting air each time on the L rear. No obvious leaks or place where air can enter.

Any ideas?

sandm
11-12-2010, 01:24 PM
bad wheel cylinder there or possibly a bad connection on the brakeline? perhaps loose line at the master cylinder or the abs pump if it has? no tiny leaks at any rubber hose-to-metal line joints?

with the bleeder tight, if someone pumps up the brakes hard, no leaks anywhere I assume?

I do know from experience if you are going to mess with the brake lines at all, spend the few $$ at harbor freight for the actual wrenches that do brake lines. you'll strip them out if you don't :)

maxpower220
11-12-2010, 02:54 PM
2 ways that I would attack:

1. Go purchase a brake bleeder kit and push the fluid from the wheel up to the master. Air wants to rise and that is the sure way to get everything out. Also, you can use the bleeder to ensure pressures and aid in finding a leak. Costs vary based on the quality that you buy.

2. Purchase some speed bleeders (one way check valves in the wheel cylinder) for a four wheels and pump fluid to all wheels at the same time. This will waste a lot of fluid, but it works great for getting air out and firmness in the peddle.

If there are no other leaks around the master, the hoses, the connections, or the wheels, I can't offer more than that.

newty
11-12-2010, 03:09 PM
2 ways that I would attack:

1. Go purchase a brake bleeder kit and push the fluid from the wheel up to the master. Air wants to rise and that is the sure way to get everything out. Also, you can use the bleeder to ensure pressures and aid in finding a leak. Costs vary based on the quality that you buy.

2. Purchase some speed bleeders (one way check valves in the wheel cylinder) for a four wheels and pump fluid to all wheels at the same time. This will waste a lot of fluid, but it works great for getting air out and firmness in the peddle.

If there are no other leaks around the master, the hoses, the connections, or the wheels, I can't offer more than that.

That would be the best route. You can get all that fairly cheap.

Razzman
11-12-2010, 03:15 PM
Kane, exactly how are you bleeding the brakes? I was a brake mechanic for 10 years and as already said, pressure bleeding is the best way to do it. Second would be to top off the fluid, pump up the brakes (assistant) then pump three times and hold the pedal down and barely crack the bleeder valve and close it before all the bubbles stop, repeat until no more. Then move to the other front, then do rears. It sounds to me like you're letting air back into the system by holding the bleeder open too long. If in doubt attach a clear hose to the bleeder and submerge the other end into a jar of fluid, that will prevent air getting back in.

lsvboombox
11-12-2010, 03:54 PM
does a 95 saturn have a vacuum booster? does the brakes feel real spongy with the car off, then when the car is running they firm up a bit? I would try bleeding with the ingnition on (doent have to be running)so the vacuum booster is cleared.... Also sears sells brake bleeders like mentioned above but you hook them up to the caliper and pull the fluid to the wheel and like razz mentioned the sears bleeder has a reservoir to keep air from getting sucked back in.......

Also if you try the pump method again use slow pumps... fast pumps break up the airbubbles making it harder to get them out....

kaneboats
11-12-2010, 04:45 PM
Kane, exactly how are you bleeding the brakes? I was a brake mechanic for 10 years and as already said, pressure bleeding is the best way to do it. Second would be to top off the fluid, pump up the brakes (assistant) then pump three times and hold the pedal down and barely crack the bleeder valve and close it before all the bubbles stop, repeat until no more. Then move to the other front, then do rears. It sounds to me like you're letting air back into the system by holding the bleeder open too long. If in doubt attach a clear hose to the bleeder and submerge the other end into a jar of fluid, that will prevent air getting back in.

I had the clear hose attached and the other end submerged in brake fluid. Was cracking just long enough to let some out and nothing back in.

The brakes seem to pump up pretty well and then when the car starts the pedal softens up a lot. I lose the whole top half of the pedal.

lsvboombox
11-12-2010, 04:46 PM
some more saturn specific info

http://www.saturnfans.com/forums/showthread.php?t=104304

moombadaze
11-12-2010, 07:21 PM
If I have some time tomorrow I get some of the guys to read this at work and see what they say. Send me a text to remind me sometime tomorrow

harmsway
11-15-2010, 09:49 PM
The brake bleeding sequence on most Saturns are R-rear, L-front, L-rear, R-front. If you bleed from R.R then L.R & so on it will be nearly impossible to bleed out. Also make sure the rear brakes are adjusted up snuggly with wheels off the ground, you should be able to hear the brakes drag when you spin the wheels. This could account for some of the loss of pedal or trapped air could also. Most Saturns have a pretty good pedal unlike other GM's. If you have ABS brakes it is possible that air is trapped in the ABS pump which you would almost need to activate the ABS pump with a Tech II diagnostic tool inorder to remove trapped air with-in the ABS pump. Hope this helps.

kaneboats
11-18-2010, 12:06 PM
Just got back to this. Had to go out of town for a couple days. That sequence makes no sense to me. I wonder why the L. Front which should be closest to the master would be second in line?

harmsway
11-18-2010, 01:23 PM
On Saturns & most front wheel drive vehicles the chambers in the master cylinder control left front brake & right rear brake & so on, so if you loose one of the chambers, you still have one front brake & one rear brake working. Unlike older cars & most rear wheel drive vehicles, which each m/c chamber controls front brakes & rear brakes. There for you have to bleed the brakes in the proper sequence in order to get the air out. I did double check on the bleed sequence for the '95 Saturn sc2 on Mitchell repair site. And it is RR, LF, LR, RF. I have seen many tech's get stumped when bleeding brakes after replacing hydrolic parts in the brake system with low pedal or can't get the air out until the proper bleed sequence is performed. Not saying there is not another problem, but I would try this 1st.

kaneboats
11-18-2010, 01:57 PM
Thanks very much for this. I'll try it tonight and let you know. Definitely worth a shot. Daughter is getting more humble with all the walking though. :)

maxpower220
11-18-2010, 05:01 PM
Didn't she become more humble when you broke her arm?