HELP.... Brakes
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Instructor
Joined: Sep 2003
Posts: 135
Likes: 3
From: Santa Monica, CA
HELP.... Brakes
Pardon my ignorance, but is there a over-pressure relief valve for '81 SC Brakes? So that's my short questions. Here's the backstory...
In prepping my car for the track for 01/30, I was using a Motive power bleeder yesterday to bleed my brakes. I pressurized the system to approx. 20 psi (was this too high?) and proceeded to the rear of the car to bleed the right rear.
At the same time I was opening the bleeder valve, I heard a massive hissing coming from the front of the car. FYI - some fluid did come from the valve, but I quickly closed it. Thinking something came loose on the pressure bleeder, I investigated but found nothing wrong.
I looked down at my feet and there was a large puddle forming infront of the right front tire. I couldn't immediately identify where it was coming from. After jacking up the front, it appears to have come from a small plastic hose that terminates immediately behind the front valance on the driver's side.
Nothing else looks wrong. All connections are fine. The brakes work and the pedal is very hard (I like it that way). So back to my original question, is there a pressure relief mechanism if the system gets over pressurized? Or did I just break something I can't see. I looked in the Haynes manual and don't see anything.
The last thing I want to have happen is have the brakes go out on me. Please help.
thanks,
Matt
In prepping my car for the track for 01/30, I was using a Motive power bleeder yesterday to bleed my brakes. I pressurized the system to approx. 20 psi (was this too high?) and proceeded to the rear of the car to bleed the right rear.
At the same time I was opening the bleeder valve, I heard a massive hissing coming from the front of the car. FYI - some fluid did come from the valve, but I quickly closed it. Thinking something came loose on the pressure bleeder, I investigated but found nothing wrong.
I looked down at my feet and there was a large puddle forming infront of the right front tire. I couldn't immediately identify where it was coming from. After jacking up the front, it appears to have come from a small plastic hose that terminates immediately behind the front valance on the driver's side.
Nothing else looks wrong. All connections are fine. The brakes work and the pedal is very hard (I like it that way). So back to my original question, is there a pressure relief mechanism if the system gets over pressurized? Or did I just break something I can't see. I looked in the Haynes manual and don't see anything.
The last thing I want to have happen is have the brakes go out on me. Please help.
thanks,
Matt
RL Technical Advisor
Joined: May 2001
Posts: 11,870
Likes: 75
From: Portland Oregon
Hi Matt:
First, 20 psi in the bleeder is too much. use 12-15 psi, max.
What you discovered was the vent line from the MC reserviour that needs to be pinched closed or plugged whenever you pressure bleed the brakes.
You have not hurt anything since the excessive bleed pressure simply forced fluid out the vent. All you have to do is simply go back and pinch the line closed with some needle-nosed vise-grips and rebleed the system at 12 psi.
First, 20 psi in the bleeder is too much. use 12-15 psi, max.
What you discovered was the vent line from the MC reserviour that needs to be pinched closed or plugged whenever you pressure bleed the brakes.
You have not hurt anything since the excessive bleed pressure simply forced fluid out the vent. All you have to do is simply go back and pinch the line closed with some needle-nosed vise-grips and rebleed the system at 12 psi.
Last edited by Steve Weiner-Rennsport Systems; Jan 16, 2005 at 10:42 PM.
Advanced
Joined: Apr 2002
Posts: 57
Likes: 0
From: CT
I've done that... twice! Really annoying after being so careful at the wheels, etc.
The Motive bleeder works well. Just test how well it has attached/sealed at the MC reservoir cap to make sure it does not leak. You may not have experienced it before, but this problem may arise when you've plugged the vent hose coming from the side of the reservoir.
The Motive bleeder works well. Just test how well it has attached/sealed at the MC reservoir cap to make sure it does not leak. You may not have experienced it before, but this problem may arise when you've plugged the vent hose coming from the side of the reservoir.
Advanced
Joined: Oct 2004
Posts: 94
Likes: 0
Fellow listers:
I have just used the Speed Bleeders for the first time and could not be more pleased. Before, my wife used to sit in the car and pump the brakes for me to bleed the systems and every once in a while, I'd break off a bleeder.
Speed Bleeders have a ball and a check valve, so when you back them off 1/2 turn, they only bleed on the downstroke of bleeding the brakes!!
This makes it a one worker job and an absolute breeze!! Additionally, you can order stainless steel Speed Bleeders too, so they may not freeze up in the calipers!! Oh joy!! I liked them so much, I put them in my Jetta TDI with 217,000 miles and have lovely, clean brake fluid all the way around!!
I cannot tell how much I loved these items. I am not connected with them, but am a grateful user.
http://speedbleeder.zoovy.com/
Tom
I have just used the Speed Bleeders for the first time and could not be more pleased. Before, my wife used to sit in the car and pump the brakes for me to bleed the systems and every once in a while, I'd break off a bleeder.
Speed Bleeders have a ball and a check valve, so when you back them off 1/2 turn, they only bleed on the downstroke of bleeding the brakes!!
This makes it a one worker job and an absolute breeze!! Additionally, you can order stainless steel Speed Bleeders too, so they may not freeze up in the calipers!! Oh joy!! I liked them so much, I put them in my Jetta TDI with 217,000 miles and have lovely, clean brake fluid all the way around!!
I cannot tell how much I loved these items. I am not connected with them, but am a grateful user.
http://speedbleeder.zoovy.com/
Tom
