Author Topic: Brake Pedal Travel (Read 10273 times)

blu65 · « **on:** July 15, 2009, 09:47:41 pm »

Hope some one can offer a solution to my problem,my brake set up is as follows, xa/xb discs hq holden calipers xa/xb booster & master cyl, mustang V8 rear drum brakes,the pedals are xy hung off a standard mustang pedal box. although the car stops ok i can't stand the pedal travel ant ideas on how to firm it up ?? by the way it's a manual ;w

non member · « **Reply #1 on:** July 15, 2009, 11:54:19 pm »

Clamp off the rear flexible line & see if the pedal comes up further or is harder. If not then clamp off the fronts, leaving the rears unclamped & try again. That identifies which end is incorrect for the master.

Do that & report back here & we can go on.

Many good brake people post on this forum, so you will get an answer.

moe · « **Reply #2 on:** July 16, 2009, 09:35:40 am »

Was the booster new?
Any air in the system?

But I agree with Ozbilt, work out which end is the issue.

blu65 · « **Reply #3 on:** July 22, 2009, 11:03:58 pm »

I have clamped off the fronts and the pedal instantly improves ie firms up,remove the clamping and the pedal returns to its normal self soft & too much travel,;2, the master cyl is new(not reco)and the booster is S/H

moe · « **Reply #4 on:** July 23, 2009, 12:34:39 am »

Are your brake lines running through the distribution block?

Have a read of this article:
http://www.hoppers.com.au/brake%20kits/masters%20boosters%20brackets%20and%20pumps.pdf

non member · « **Reply #5 on:** July 23, 2009, 08:32:11 am »

Sounds like you are not getting enough volume of fluid to the front calipers. The moment you clamped off the fronts, the pedal went hard, tells me the master size is too small.

Find out what bore size the Holden master would be that suits the calipers you have & compare to the master size you have. that will be the difference.

I can get the info for you tonight if you do not get a reply here today.

moe · « **Reply #6 on:** July 23, 2009, 10:43:23 am »

Here is another thread discussing the same conversion;
http://www.mustang.org.au/forum/viewthread.php?tid=1622

blu65 · « **Reply #7 on:** July 24, 2009, 09:59:21 pm »

Hi Guys,
the mater cyl i'm using is the XB Ford P-6258A as per the information on the article http://www.hoppers.com.au/brake%20kits/masters%20boosters%20brackets%20and%20pumps.pdf[/url]
The brake lines are plumbed from the master straight to each of the front calipers(ie the two rear outlets on the master) the outlet at the front plumbed to the rear brakes as per the markings on the master.There is no distribution block,is one needed ?I thought they were only to split the fluid to the two front calipers?;w & thank you for the continuing info...;{

scott66stang · « **Reply #8 on:** July 24, 2009, 10:16:28 pm »

Have you tried clamping off the rear brakes as Ozbilt says , instead of the front ? if after this you get a hard pedal it suggests that your rear brakes may need bleeding or adjusting. If you apply the handbrake and the pedal firms it means the rear brakes need adjustment. Once you try this we can advise further.

non member · « **Reply #9 on:** July 24, 2009, 10:33:10 pm »

On your HQ front calipers, where is the bleeder screw?

If they are anything like KH single piston calipers on 68 + fords, they can be put on upside down & when bleeding it does not get all the air out. The bleeder should be positioned so that all the air will be bled out when they are bolted correctly. Worth a look.

scott66stang · « **Reply #10 on:** July 24, 2009, 10:41:08 pm »

Quote

Originally posted by ozbilt
On your HQ front calipers, where is the bleeder screw?

If they are anything like KH single piston calipers on 68 + fords, they can be put on upside down & when bleeding it does not get all the air out. The bleeder should be positioned so that all the air will be bled out when they are bolted correctly. Worth a look.

Have you ever bled the brakes on a MINI ? nightmare the bleeders are at the bottom of the wheel cyls

blu65 · « **Reply #11 on:** July 24, 2009, 10:42:01 pm »

The bleeder screw is at the top..the calipers were overhauled a couple of years ago, they sat around before they were fitted but they don't leak & seem to hold pressure ok when you hold the pedal down,i'll try & bleed them again & see what happens,any other suggestions would be welcomed.....

non member · « **Reply #12 on:** July 24, 2009, 10:51:35 pm »

Quote

Originally posted by scott66stang
Quote
Originally posted by ozbilt
On your HQ front calipers, where is the bleeder screw?

If they are anything like KH single piston calipers on 68 + fords, they can be put on upside down & when bleeding it does not get all the air out. The bleeder should be positioned so that all the air will be bled out when they are bolted correctly. Worth a look.
Have you ever bled the brakes on a MINI ? nightmare the bleeders are at the bottom of the wheel cyls

Unfortunately yes.

I did my apprenticeship at a shop where we prepared Rally, Production & Sports Sedan Minis, along with many other rally, road racing & speedway cars.

Owned many Cooper S Mini's, even had a Cooper S van, real sleeper that one. Used it for chasing & servicing rally cars. After all these years, I still love them.

Looking for a Mk2 Cooper S for a friend in the US if anyone knows of one for sale. He has a vintage MG collection & wants some more oil on his workshop floor (controlled seepage as the Poms call it).

Sorry, back to the brake problem.....

shaunp · « **Reply #13 on:** July 30, 2009, 10:21:25 am »

Have you got the right part of the master cyl feeding the right end of the car.

seany-boy · « **Reply #14 on:** July 30, 2009, 01:46:13 pm »

Hi Guys,
the mater cyl i'm using is the XB Ford P-6258A as per the information on the article ]http://www.hoppers.com.au/brake%20kits/masters%20boosters%20brackets%20and%20...
The brake lines are plumbed from the master straight to each of the front calipers(ie the two rear outlets on the master) the outlet at the front plumbed to the rear brakes as per the markings on the master.There is no distribution block,is one needed ?I thought they were only to split the fluid to the two front calipers? & thank you for the continuing info...
============================================
so Blu65, is it just pedal travel or softness you are not happy with as it is not clear? In the docs you referenced there is discussion about the XB master cylinder and what coul dcause excess travel or soft pedal and also about whether or not you need a proportioning valve to ensure correct pressure to front and back. As the guys suggest, once you recheck the basics then aim to split the system inot front and rear by locking one off to narrow down your search. also make sure no cables are crimped accidentally.

jiffy · « **Reply #15 on:** July 30, 2009, 07:21:41 pm »

Anpother thought - unclamp everything, pump the hell out of the brake pedal - does the pedal 'pump up' and get to the stage where the pedal travel is more acceptable?

If this happens, you have air in the system

jiffy · « **Reply #16 on:** July 30, 2009, 07:22:52 pm »

Also - this topic is in the wrong section - you should ask a moderator to repost in the 65-73 section for wider visibility....

MustangNut · « **Reply #17 on:** August 08, 2009, 10:51:58 am »

Hey, Blu65 did you ever get this sorted? Kinda interested as I have a similar problem.

Darryl

Brake Pedal Travel

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Author Topic: Brake Pedal Travel (Read 10273 times)