I have a 71 Duster that I'm having trouble getting a firm pedal on. Most everything is new (calipers, wheel cylinders, master, hoses, distribution block) and with a pressure bleeder, I am able to get a steady stream of fluid at all wheels. I bled the master before hand, but the pedal is still spongy. I even went fitting by fitting and cracked them open to make sure no air pockets got stuck but to no avail. I think I've put a couple gallons of fluid through the system and I'm about ready to pull my hair out! Please help...
Yet Another Bleeding Problem...
- Thread starter jar84203
- Start date
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Robbie2734
Lambcharger
Check the rubber hoses, sometimes they get soft and will balloon with pressure.
Ok, you have new hoses but they might have set on the shelf for years. They will start to dry rot. One more thing, I'm thinking you have disk/drums. Have you adjusted them all one more time? I had spongy breaks on my car (pulled the front end apart to rebuild) and bled about 3 times but couldn't get a stiff pedal. I pulled the rear drums and cleaned the dust out then readjusted them just a tad tight. Problem solved!
Ok, you have new hoses but they might have set on the shelf for years. They will start to dry rot. One more thing, I'm thinking you have disk/drums. Have you adjusted them all one more time? I had spongy breaks on my car (pulled the front end apart to rebuild) and bled about 3 times but couldn't get a stiff pedal. I pulled the rear drums and cleaned the dust out then readjusted them just a tad tight. Problem solved!
chryslerfat
Well-Known Member
As stated are the drum brakes adjusted properly? If it disc are the bleeders at the top or bottom? Calipers can be put on upside down with the bleeder down and will trap air.
67Dart273
Well-Known Member
Something left out of the advice above, have someone watch carefully as you apply the brake. Look at the master and firewall, and look up into the dash area at the pedal and master as you apply pressure. Look for flex in the (rusted) firewall, flex or bending in the linkage or pedal
Robbie2734
Lambcharger
The Summit catalog carries reinforced ones (stainless sleeving around rubber) , yes it can be a problem. Have someone step on your brakes and watch the hoses flex! But I think you have air trapped in the system somewhere. I would look at the front calipers. Get a large c clamp and pull the passengers side caliper, clamp the piston into the caliper with the clamp. Now try bleeding it with the bleeder at the highest point. Put it back together and repeat on the other side.
I'll have to try this...
PanGasket
has cork sides
Maybe your proportion valve is the incorrect one for the application? This can be a symptom of this
If the above tips don't help. Try this.
Remove the lines on the master and plug off the ports. (Use steel inverted flare plugs, available at any GOOD auto parts store). Pump the pedal a few times and it should go rock solid. If it doesn't, bad master.
If it does go solid, hook up the front brake line. Test the pedal, (you may have to bleed the system again). If you get a good pedal, the problem is probably with the rear brakes.
(Obviously).
Either way, it narrows down where the problem is.
You could go farther and cap off the hardlines where they connect to the flex hoses to see if there is a possible problem with the hardlines themselves. (Pinholes or whatnot).
Remove the lines on the master and plug off the ports. (Use steel inverted flare plugs, available at any GOOD auto parts store). Pump the pedal a few times and it should go rock solid. If it doesn't, bad master.
If it does go solid, hook up the front brake line. Test the pedal, (you may have to bleed the system again). If you get a good pedal, the problem is probably with the rear brakes.
(Obviously).
Either way, it narrows down where the problem is.
You could go farther and cap off the hardlines where they connect to the flex hoses to see if there is a possible problem with the hardlines themselves. (Pinholes or whatnot).
Even though the parts are new, double check for leaks. Take a look from inside, where the master cylinder is mounted to the firewall. The master will leak from the back. Check the wheel cylinders also. Its not uncommon for new parts to be bad and leak.
GMachineDartGT
Senior Member
Bleeding a completely new dry system can be a challenge. The correct way is to use an air powered pressure bleeder. This pressurizes the M/C, and makes life real easy. There are much cheaper versions using a plant sprayer for pressure. If that is not available, bleed each connection, one at a time. Master, prop valve, etc. Hope that helps.
chryslerfat
Well-Known Member
And the #1 rule for bleeding is start at the longest line 1st.
Absolutely a good rule to follow. Although it was more of an absolute on older 4 wheel drum cars with a single reservoir master. All of the lines were connected. On the new build brake systems I do, I will actually start at the closest wheel and work my way out just to get some fluid flowing and a little pedal happening. Then I go for the final bleed, farthest to nearest.
2 Darts
A-body Addicted
This one drove me crazy before I figured it out. If the bleeder is at the bottom, push the piston as far back in the caliper as it will go. Remove the right caliper first. I used a very large C-clamp to hold the piston in place and then bled it holding the valve higher than the hose. Remove clamp and re-install caliper. Repeat with the left side. The first pedal push went all the way to the floor and the master cylinder needed to be topped off before completing the left side bleed.
Um, if the hose is on the top, and the bleeder is on the bottom, couldn't you just switch the calipers from side to side?
chryslerfat
Well-Known Member
Correct if the bleeder is not at the top you have the caliper on the wrong side.
wow...I know the pain...are you using a Strange master by any chance????...had similiar problem with the HemiDemon I worked on...changed all but kitchen sink...finally got one of the Mopar alum (knock off) master cyl (1.25) and got great pedal (stiffer than a wedding pecker)...but STILL (as far as I know) fighting a clamping issue on rear...rear wheels off ground..in gear(auto)...and you have to pump/push like crazy...just to get the wheel to stop spinning at idle...brake line pressure good...I say it points to rear calipers(right stuff)...maybe I didn"t adjust their E -brake properly and pads have to far to travel???...but back to spongy pedal....I sent all 3 Strange Master cyl back to them.
chryslerfat
Well-Known Member
Is the OP anywhere near one of us that would be willing to stop by and give him a hand?
no kiddin"...I had to fluff my wife for a week to get her "pedal pushin" for a couple of nights..then my brother drove down(225 miles one way) to take over...almost made it "fun"...too bad my compressor didn"t have the pressue/volumne to handle the air bleeder...I only spent a couple of hours trying that one.
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