Booster or master?
#1
#2
#3
Got it hooked in .Thanks
Also wanted to know ,--- I did a full bleed before the work on the rear an still have air/ spongy pedal an a squeek when I let up on pedal,is a bit spongy still .Also the rubber diaphram on brake fluid cap is getting sucked inward fast.
I also notice a slight change in idle at the stop light.
Does that sound like the booster going bad? Or master cylinder? Both?
Also wanted to know ,--- I did a full bleed before the work on the rear an still have air/ spongy pedal an a squeek when I let up on pedal,is a bit spongy still .Also the rubber diaphram on brake fluid cap is getting sucked inward fast.
I also notice a slight change in idle at the stop light.
Does that sound like the booster going bad? Or master cylinder? Both?
Last edited by hidden1; 04-21-2020 at 08:56 PM.
#4
#5
Rebled everything an a tiny bit of air but not a lot.
I still hear that spring as I pump them.Faint hum.
After retightening the line after letting any air out ,on each bleed,that pedal lost all pressure fully.
No oil in the booster line to engine an the 1way valve was clean an working.
Note n last line,when bleeding, at drivers side front, the cap on the brake fluid cover colapsed in.
Does it sound like the master cylinder plunger an or booster is weak ?.I did 3 tests on booster an seemed ok but I bet theres a leak internally somewhere .
What should I look at testing an checking next .An what steps.
thanks
I still hear that spring as I pump them.Faint hum.
After retightening the line after letting any air out ,on each bleed,that pedal lost all pressure fully.
No oil in the booster line to engine an the 1way valve was clean an working.
Note n last line,when bleeding, at drivers side front, the cap on the brake fluid cover colapsed in.
Does it sound like the master cylinder plunger an or booster is weak ?.I did 3 tests on booster an seemed ok but I bet theres a leak internally somewhere .
What should I look at testing an checking next .An what steps.
thanks
#6
Booster or master?
On my 01 3.9 2wd I'm getting a regular spring like squeek noise in brake pedal an a lot of air in the pedal though I've bled the brakes a lot..Sounds like in booster but not sure.Spongy pedal w air .
After bleed pedal is very loose floose maxed all air from the 4 bleeders.
Also on last bleed in front drivers side the cap rubber seal collapses in ..An has after driving .
Does this sound like a failing booster or maybe cylinder internal leak ,or both an what should I look at /test?
Thanks
After bleed pedal is very loose floose maxed all air from the 4 bleeders.
Also on last bleed in front drivers side the cap rubber seal collapses in ..An has after driving .
Does this sound like a failing booster or maybe cylinder internal leak ,or both an what should I look at /test?
Thanks
#7
Trending Topics
#8
I dont have the abs on my scanner.I may get one later though. Im getting no abs or brake light error, or codes .
Pedal sinks,[but a little pressure], unless pumped an at release the springs squeak.Hum noise a little. As testing it with a person the squeek was around the booster .Something is causing that cap to collapse in after driving also.
I got another booster to try on it ,but wanted some insight 1st.
Does a leak in the booster cause a small hesitation ,sometimes ,as sitting at a light in drive,due to air from the booster hose to intake?
An how do I do a bench test on tge booster off the truck?
Thanks for the suggestions.
Pedal sinks,[but a little pressure], unless pumped an at release the springs squeak.Hum noise a little. As testing it with a person the squeek was around the booster .Something is causing that cap to collapse in after driving also.
I got another booster to try on it ,but wanted some insight 1st.
Does a leak in the booster cause a small hesitation ,sometimes ,as sitting at a light in drive,due to air from the booster hose to intake?
An how do I do a bench test on tge booster off the truck?
Thanks for the suggestions.
Last edited by hidden1; 04-22-2020 at 07:09 PM.
#9
If the booster was bad, the pedal would be 100% stiff just like with engine off. The connecting rod between the pedal and the plunger is a fixed length, it's not going to collapse or anything. All it does is move back and forth in the housing (research how a diaphragm booster works). A spongey pedal with engine running means either the booster is working at 100% or the master or ABS unit has a seal bypassing internally. A spongey pedal with engine off points 100% to the master or ABS having a failed seal.
#10
Rebled everything an a tiny bit of air but not a lot.
I still hear that spring as I pump them.Faint hum.
After retightening the line after letting any air out ,on each bleed,that pedal lost all pressure fully.
No oil in the booster line to engine an the 1way valve was clean an working.
Note n last line,when bleeding, at drivers side front, the cap on the brake fluid cover colapsed in.
Does it sound like the master cylinder plunger an or booster is weak ?.I did 3 tests on booster an seemed ok but I bet theres a leak internally somewhere .
What should I look at testing an checking next .An what steps.
thanks
I still hear that spring as I pump them.Faint hum.
After retightening the line after letting any air out ,on each bleed,that pedal lost all pressure fully.
No oil in the booster line to engine an the 1way valve was clean an working.
Note n last line,when bleeding, at drivers side front, the cap on the brake fluid cover colapsed in.
Does it sound like the master cylinder plunger an or booster is weak ?.I did 3 tests on booster an seemed ok but I bet theres a leak internally somewhere .
What should I look at testing an checking next .An what steps.
thanks
That springing sound you hear is normal for drum brakes. The engine normally covers it up. Nothing to worry about provided it's all put together properly.
The front cap collapsing is normal. The cap's purpose is to limit air intrusion into the master cylinder. Air itself isn't a problem (unless you let it go dry) but the moisture in the air is. Brake fluid is hydroscopic, which means it absorbs water, and water in the brake lines causes all sorts of problems. It will corrode the inside of the lines, and when the brakes are used hard it will vaporize from the heat. Water is not compressible, but steam is, so when there's water in the lines hard brake usage will result in no brakes. When I bleed them, I usually refill the master cylinder about every 15 pump cycles.
If you have antilock brakes, you may have to get them flushed by the dealer unless you have access to a tool that will open the valves. There's a procedure that goes with flushing the ABS unit.
If there is an internal booster leak, there's typically a hissing sound that goes with it. It's loud and you won't miss it if it's there. And, if there's a master cylinder leak, you should be losing fluid.
Hope some of this helps.
Last edited by Vimes; 04-22-2020 at 09:53 PM.