PDA

View Full Version : Brake Booster question



Hidden lights
04-16-2016, 03:33 PM
Hi, i need some help about my brake booster. I could hear a hissing sound each time i hit the brakes and they stay there as long as tje pedal is depressed. So i reckon it must be my booster, i do quick tests, as instructed by the Service Manual eg., press the brakes while engine off; press while engine on etc etc. The booster (including the check valve) passes all tests but the hissing sound is still there. I also need extra leg muscle to get the brakes going.

Any clues ? Can it be that the booster is faulty even with negative findings on the test methods ??

Tia

Les

conozo
04-16-2016, 07:10 PM
I think your seeing the early stages of brake booster failure, the real test would be to apply a vacuum to it and see if it holds it.

Hidden lights
04-16-2016, 10:52 PM
Thanks Conozo, does the booster have a repair kit sold in the market or is it the throw away type "beat the hell out of it" when it goes ??

By the way, is that yours in the picture ?? Nice ride !!!

conozo
04-17-2016, 04:15 AM
There used to be rebuild kits available but I haven't checked. I see you can get a reman one for about $80, return your old one as the core refund.

FYI. There is a difference between the carb and FI models, the FI is larger.

Yep that's my car, thanks. I go for a nice classy look.

AC439
04-18-2016, 11:53 AM
I'm trying not to steal the thread but I think I have same problem. When I pulled vacuum directly on the vacuum port at the brake booster (without the check valve, the valve checked fine), it does NOT hold a vacuum. I could keep pulling air from the booster without any resistance. This was done when engine off. Does it indicate my booster is bad ? I would imagine a normal booster will hold vacuum, right ? Also, where can I get a booster for $80 ? I checked and its around $150. (My car is 86 LXi) Thanks.

conozo
04-18-2016, 12:55 PM
Yes your booster is bad if it won't hold a vacuum. I saw some on rockauto.com for around $80 and we have a rock auto coupon here on 3geez that you can use.

AC439
05-20-2016, 06:57 AM
I ended up replacing both the booster and MC from advance auto. Brake is much better now and it also solve the manifold pressure issue. I have updated my other thread on connecting both vacuum advance ports to manifold. I try not to buy things from rockauto if I don't have to. Their catalog system is poorly referenced sometimes and had bad experience with wrong parts.