Brake Problems

Rick)rox · Post by **Rick)rox** » Fri Nov 17, 2006 7:20 pm

Situation, my braking system can't hold pressure. Whenever I press on the brake pedal it goes half way and I hear a puff of air and lose pressure. I've replaced the master cylinder : no luck. Now I'm thinking the problem might be the Vaccum booster. Reason being is that I've rebuild all my brake calipers also. and replaced the hoses that go from the brake line to the brake caliper. Not leaks anywhere, and no pinches in the line. Help?

So Cal Mark · Post by **So Cal Mark** » Fri Nov 17, 2006 8:12 pm

sounds like you still have air in the system. When you bleed the rear brakes you have to support the axle or disconnect the compensator linkage and push it up. Otherwise you'll never get the air out of the rear brakes. Normally when boosters fail you have a very hard pedal

Rick)rox · Post by **Rick)rox** » Fri Nov 17, 2006 8:31 pm

What do you mean by support the axle, and whats the compensator linkage lol. Sorry i'm pretty new with cars.

manoa matt · Post by **manoa matt** » Fri Nov 17, 2006 9:35 pm

Chech out "International Auto Parts" at the top of the home page click on "Technical Bulletins" under Fiat go to brake system. Click on the first article it gives a picture of a rear brake compensator and describes the process of bleeding the rear brakes. Very informative

good luck

matt

Rick)rox · Post by **Rick)rox** » Sat Nov 18, 2006 1:19 am

Okay, well that didn't help much. When I jacked up my car I put jack stands under the axles it didn't even occur to me that I need to do that =P

tanis · Post by **tanis** » Sat Nov 18, 2006 1:48 pm

I agree with Mark -Keep bleeding the system, you've still got air in there somewhere. There is a procedure/order for doing it correctly, but it escapes me at the moment -maybe someone else will chime in. Doesn't sound like a booster to me..only other thought is that you may have a leak in the line, but I imagine you'd have seen that.

racydave · Post by **racydave** » Sat Nov 18, 2006 6:06 pm

Marks right, you still have air in system. My 79 was a b----. Get someone to gently push brake pedal, crack open the lines at MC and bleed all lines at MC. I would gravity bleed the l/r then r/r,r/f, thenl/f. You probably will still have air, have someone help press brake pedal and re bleed. Ive seen other kinds of cars that were also very difficult. Its funny, my 79 is the only car ive ever been able to bleed the L/R by myself, if you stretch, you can reach it! Good Luck!

Rick)rox · Post by **Rick)rox** » Sat Nov 18, 2006 9:57 pm

Ok, I will try that and get my friend to help me.

pertyfly · Post by **pertyfly** » Mon Nov 20, 2006 11:47 am

Wait a second....he said he hears a puff of air and it loses pressure. The first time I read this, I immediately interpretted this as the booster.

By "losing pressure" he probably means it stops braking as well (meaning you need to press harder).

I just found with mine that when I press the pedal and release it, depending on pedal position I get "puffs of air" as well. Mine is not so bad as to affect braking terribly though I do know it's a bit harder to brake. It's just a bit more like manual braking for me

I was actually wondering if there is a seal, or if the booster is totally shot.

Anyway, I just thought I had to interject since I'm pretty sure that is actually what he's talking about.

Chris

Rick)rox · Post by **Rick)rox** » Mon Nov 20, 2006 8:19 pm

Hm, I've never driven the car before. I brought it home on a car dolly. And when I hear the "Puff" the car isn't started. Also I hear that sound when I press on the brake before I hit the floor not when the pedal is coming up.

So Cal Mark · Post by **So Cal Mark** » Mon Nov 20, 2006 10:35 pm

the puff is air coming thru the filter on the back of the booster. The reason he hears it is because the pedal is moving too far. When a diaphragm moves, it displaces air on the other side. All boosters have a filter where the pushrod from the pedal attaches.

Rick)rox · Post by **Rick)rox** » Sat Nov 25, 2006 9:32 pm

No luck and a cramped right leg. I went to auto-zone today to see what they had to say. He told me to start at the caliper closest to the master. And that I need to pressurize my master [or something to that effect] And last but not least man told me that I needed to have my car running for the booster system to bleed them. We've been only bleeding the back could my compensator valve be defective?

So Cal Mark · Post by **So Cal Mark** » Sat Nov 25, 2006 9:41 pm

are you getting pressure when you bleed the rear calipers? If you're not getting much fluid, disconnect the link from the compensator to the axle. Push up and retain the link as high as it will go. That will allow full pressure to the rear brakes. If you don't do this, you'll never get the rear brakes bled.

Rick)rox · Post by **Rick)rox** » Thu Nov 30, 2006 9:52 pm

Giving up, btw selling the car

check it out.

So Cal Mark · Post by **So Cal Mark** » Thu Nov 30, 2006 10:26 pm

sorry to hear you're giving up so quickly. There just aren't many short cuts you can take when making repairs, so sometimes it takes awhile to get them right

Brake Problems

Brake Problems

bleeding rear brake lines