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Previous Next Up Topic Public / General Discussion / soft brake peddle (19922 hits)
By JACK 1467 Date 2014-05-14 22:39 Edited 2014-05-14 23:45
I put all new disc brake parts on the front end ,new master cyl,  I bleed the brakes 6 7 tmes  but still the same thing soft peddle go's right to the floor , If I pump it the brakes it get harder.
I installed the 2lb res vol 
still the same .I'm at witends .
what I'm  doing wrong
By Paul G Date 2014-05-15 01:43
I would start with checking the pedal free play at the master cylinder. When the pedal is released the master cylinder needs to come all the way pack so that you can feel a little play before the pushrod starts pushing the piston inside the master cylinder. Any amount will work, but zero or a negative number of any size will not work. The brakes won't bleed correctly and you will never chase the air all out.

Next I would check of the rear brake wheel cylinders. Make sure they are not leaking. It is not uncommon for bleeding the brake to find nearly worn out wheel cylinders and push them over the edge to leaking (dislodge built up corrosion.)

If both of those check out I would replace any remaining old flex hose. You have 1 at each corner and I bet you replaced 2, but how about the back two? These hoses can do weird things as they fail, making strange 1 way valves with leaks as the inner rubber come loose from the pressure reinforcement layer in different ways. That can cause braking issues, but is even better at causing bleeding problems.

At this point everything but the hard lines should be new or verified working. The brakes should bleed unless you suffered the misfortune of getting a bad new part. With the cheap crap out there it is too possible. I generally buy only Varga (Brazil, an original VW supplier) or German brake parts due to quality issues.
By JACK 1467 Date 2014-05-15 12:35 Edited 2014-05-15 12:37
I will be looking in to the rear cylinders , but  I did replace the rear cylinders a year or so but I'll still look in to it . the play is fine in the pedla  I got to that the other day.
I was looking to get some rear lines to stanless steel .
as for the master cyli this s the #2one   I called the com(chirco) I  recived the kit from he told me I need a bigger 14mm bor master cyl for the disc brake kit I have, and still the same .
I'll try the rear lines frist and hope it workes. I'm going to have a pal come over so I can see if the rear lines do sewell as the pedal go's down.
I wont stop till I find the probliem hope it all works sick of working on it I want drive it ths summer. 
thank you
jack,
By Ron S 3875 Date 2014-05-15 13:56
Last time my bug did that to me I found a small break in the lint to the rear, under light pressure it would open a bit.  Had to replace the whole steel line.  Since having had that happen I check every line for pitting when I do brakes on any buggy.

Not sure on your procedure for brake bleeding (I.E. rear first, pump-open-close-release, or power bleeder) but would suggest obtaining the power bleeder kit from Harbor Freight, it sure makes the job much easier and more positive all bubbles are out.

When you re-bleed the brakes do you see bubble in the output tube to your waste bottle?  If so a leak is somewhere.

Is the disc brakes stock or an upgrade?
  If upgrade did you put in a master with dual ports and one having a proportioner valve or add an external proportioner valve for the disc pressure difference?
By JACK 1467 Date 2014-05-15 23:45
I used a 2 lb proportion valve on both sides but still soft to the floor,
yes I do see bubbles in the cup , but wait if bleed the 2 fronts  I'll fill up the cup with eas,
  so what do's that tell you it might be .I have no other leaks that I can find 
after market kit with a 14mm dual port made for disc's .
so today I took it all the rear drums  apart to see if the back drums are leaking  nothing  dry as a bone both sides.
do you think I should use white tefline tape on all my fittings. 
I have no clue  what to do next .
By Brad H 1498 Date 2014-05-16 02:41
NO do not use teflon tape on the brake fittings. They seal on the flare and seat not on the threads. There has been problems with masters sucking air past the fittings that go to the resevoir. I would remove those fitting and was he everything good with brake clean. Then apply some urethane sealant such as Right Stuff from Permatex to the fitting JUST at the top of where it sits in the grommet.

When bleeding the brakes use 2 people. Open the right rear bleeded and who ever is back there stick there finger over the bleeder valve tightly. When the pedal is depressed it will push air and fluid out but your finger will seal it up when the pedal is released. Keep pumping you get good fluid flow and there is very little air. Then bleed them by pumping the pedal 3 times and holding it down, then opening the valve till the pedal hits the floor and close the valve before releasing the pedal. Repeat on the left rear. IF the system is all new and clean I reuse the brake fluid that gets pumped through. Just let it sit and let the air settle out of it. On the front disks take the calipers off and stick something solid in between the pads to keep the pistons from pushing out. Lift them up with the bleeder screws being the highest point and bleed them. Again start by holding a finger over the open bleeder until there is good fluid flow and little air. Then bleed them using the 3 pump method above.

brad
By LoCashJohn Date 2014-05-20 15:40
Two things:

For disc brakes, I think the correct MC bore size is 19 or 21mm. Double check that and see what MC you have installed.

When bleeding brakes, adjust your drum brake shoes out as far and tight as they can possibly go. I mean so the wheels can hardly turn. Now bleed the brakes. Once you think they are bled out, push the brake pedal as hard as you can. I mean until you're red in the face and you think you're gonna break the pedal.  Now check the drums and see if they spin. If they do adjust the shoes out more and bleed the brakes again. Once you have no more air in the system, adjust the shoes in just enoug that you hear a slight or occasional rub as you spin the drums.   Now try driving and see how the pedal feels.

FYI, discs on the front of a buggy are going to lock up real easy.
<a href="http://www.LoCashRacing.Org">http://www.LoCashRacing.Org</a>
More brains than bucks...
By JACK 1467 Date 2014-05-21 23:07
thanks for all that, as soon as I get the new parts I'll give it all a try .
you guys are the best .
thanks
jack.
By JACK 1467 Date 2014-06-10 23:42 Edited 2014-06-10 23:46
OK ,  put all new parts in.
I installed a singel port master cyl , and now the fluid comes out of the  top of  the cap(littlehole)
as I step on the brakes .WTF no matter what I do with this *%$# thing. disc in front drum in back
the pedle go's right to the floor no matter what I do , gettng fed up with this .
By Brad H 1498 Date 2014-06-11 02:55
Do you have some freeplay in the brake pedal? There should be about 1/8" of freeplay before the pushrod touches the piston in the master.  There should be a bit of fluid pushed up in the resevoir when the pedal is pushed not a lot but a bit.

A single circuit master is not going to move enough fluid for disk brakes. You really need a dual circuit master, prefably one of the large bore masters listed by John.

brad
By JACK 1467 Date 2014-06-11 13:51
I tryed it all ,
the single master came with it  so I said lets give a try ,
I'm going to remove the single master and check the free play and reInstall the dule master.  I'm realy lost If this dosnt work. it was like a strem of fluid as I pump the pedal
By Ron S 3875 Date 2014-06-11 14:13 Edited 2014-06-11 14:45
Jack 1467
As I had asked before have you checked the entire steel brake tube running from front to back.  All focus seems to keep looking at back end or front end, but not the line in the middle.  As I had previously stated years of exposure to moisture  and dings and dents can damage the line.  It can get plugged or partly plugged, leak and even break.  I have twice seen fluid come out the rear on a bleed job but yet had weak or no brakes in rear and soft pedal pressure.  That after hours of bleeding pump and working on the system I finally pressed hard enough to burst the line totally next to drivers seat.  After pulling line I found several leaking holes and artery rust that while it worked partly it was a disaster waiting to happen.
If your ride is over 25 years old and your replacing and upgrading brakes do not for get the forgotten $25 line that in hidden in the car.  Shame if it bursts at the red light on a busy intersection.

If you installed a new brake system on the front why not replace the line front to back.
As for the leak out the top of master very common issue getting the reservoir line to make a good stopper fit.  And if pressure is high in the system do to line clogs or blockage back up of fluid can occur.
By JACK 1467 Date 2014-06-11 15:53 Edited 2014-06-11 15:57
All the lines are new from front to back , no holes at all ,check all the lines, went over them time after time  to see if I can find what is wrong  I had a pal 5-10-14come over to help me to see If I was missing some thing.
you said some thing That I might try , I"ll  blow out the lines just to be on the safe side .
All new brake parts in rear and in the front S. Steel lines front and in the back .what I'm I missing .
and the free play is fine went over that today.
By LoCashJohn Date 2014-06-11 22:57
How old are the rubber flex hoses in the system?  When they get old and mushy on the inside (you can't really tell from the outside) they will give the same symptoms.

To test them, remove them from the car, wipe them clean and blow through them one by one. Not with compresses air, but with your mouth. It should be like blowing through a straw. If there's any resistance at all, replace them.
<a href="http://www.LoCashRacing.Org">http://www.LoCashRacing.Org</a>
More brains than bucks...
By JACK 1467 Date 2014-06-12 11:55
the flex lines are All replaced with flex stanless steal lines.
By Ron S 3875 Date 2014-06-12 14:29
Jack what is your location?
By JACK 1467 Date 2014-06-12 15:17
new jersey  middlesex county
By JACK 1467 Date 2014-06-12 18:11 Edited 2014-06-12 21:31
I think I got it,
after going over it bit by bit I found that the piton rod on the brake pedal the adjuster nut was so far out
that it would hit the top of the in side of the master cyl,
it was not letting the piston to push all the way in for the brakes to work right . find it after my pal go's so have to wait till friday to  bleed the brakes  to get it done.
then I find the brake spring in two so I go to home depot to find a conpressing spring to fit  
  around  the brake  piston rod, work's fine .(one spring inside another)
for you guy's  out in buggy land  home depot has it . 
By LoCashJohn Date 2014-06-14 02:44
If you don't mind, post a pic of the brake pedal pushrod. It sounds like it may not be stock or might have been cut downin years past.
<a href="http://www.LoCashRacing.Org">http://www.LoCashRacing.Org</a>
More brains than bucks...
By JACK 1467 Date 2014-06-14 13:21
Give me a day or two and I'll post a pic of the push rod and the compressing spring on how it works on the push rod.
I think I still might have the same soft pedal after all that hard work.
I'll get back to you
thanks.
jack.
By Paul G Date 2014-06-15 18:11
I haven't had the spring wrapped around my brake pedal cluster for years. The return spring inside the master cylinder is more than enough to push the pedal back unless the pedals are starting to seize. The real issue with not having that spring is that the brake pedal free play rattles a little when driving, not a big issue in a open buggy.
By JACK 1467 Date 2014-06-17 18:03
It works just fine . got rid of All the Bugg's get Bugg's vw.
well I went thru It Over and Over till I found it .
It was the brake  push rod the hole time . I love it it stops on a dime.
for  All you guy's that helped me out 
Thanks,
jack.
Previous Next Up Topic Public / General Discussion / soft brake peddle (19922 hits)

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