Hey there guys. I am new to this board. I purchased an 87 IROC about 5 years ago. Has always been my dream car. I let it sit for 3 years because I was pregnant and then I didn't want to put the baby in the car. Anyways...my husband wants to get it back on the road. He redid the whole brake system (except for the main brake line). Calipers, roters, pads, hoses. He bled the brakes and the petal was soft. He replaced the master cylinder and still the brake was soft. We had a mobile mechanic over here, he bled the brakes and when he pushed on the pedal it was soft. He said that the booster was bad. So my husband last night put a new booster in. Still, the pedal is soft. What else could it be? A friend told me that you needed to have the car running when you bleed the brakes. Is that true? It is a 350 tpi. Any help is much appreciated. My husband is so frustrated but we can't afford to put it in the shop. Thanks guys.

Wendy

 

Welcome aboard. You don't need the car running to do this but it may take a while. The dealer can pressure or vacuum bleed the system for about $30-40 and I'd give that a shot. I will also tell you that your rear disc calipers are probably frozen up from sitting and not being used, causing them not to work right. You might look into rebuilding them with the recall kit (search: Recall kit).

Good luck!

Ed

 

My husband redid everything. The calipers, pad, hoses, roters master cylinder and brake booster are all new. We had a professional mechanic come out and bleed the brakes for us. Once he stepped on the pedal and it went straight to the floor he said that it was the brake booster, so my husband replaced that. But it is still going to the floor, when it is running. It also idles when you press the brake. We don't know where to go from here.

 

I will also assume that you essentially drained the system..did you bench bleed the master? Sometimes air can get trapped in them and lead to this. I'd just keep bleeding and rebleeding the system. That's all I know to do to it.

Ed

 

The whole system has been drained. The master cylinder was bench bled, but when he put it on, trying to get the hose attached he lost a lot of fluid. Would that have caused air to get into the mc?

 

could have been. I'd start from the RR corner, bleed it til you get no air, and then go to the LR. then the RF, and the LF, until all the air is out. he does know how to bleed brakes, right? like, you pump up the pedal until you get some resistance. then let the bleeder screw loose, and tighten it again before the pedal hits the floor. if it's going to the floor, there's air somewhere. if it's idling when you hit the brakes, like, the idle is dropping when you hit the brakes, then your booster is probably pretty good, it's just sucking a lot of vacuum and putting some load on the motor. (meaning, fairly normal). Ed would know more than me, though.

 

The brake lines to the calipers are bled. All new fluid has gone through them. My husband bled them and then we had a mobile mechanic come and he bled them until there was no air in them.

We are going to work on the master cylinder tomorrow and bleed it and see what happens. We are hoping that the air is in the mc.