Brake issues - solved?

Brown Bear · Post by **Brown Bear** » Wed Jun 25, 2008 10:18 am

I am in the habit of braking more than once on approaching an intersection or lights as opposed to braking all the way - Problem is the pedal seems to 'ratchet' up every time the brake pedal is depressed.

Anyone had this problem?

I'm thinking either an internally leaking brake master cylinder or booster (VH44) as I'm not losing fluid, locking up or pulling drastically to one side.

Any ideas?

Cheers,

Matt

Devilrod · Post by **Devilrod** » Wed Jun 25, 2008 12:43 pm

Adjust all your brakes. If the booster is not working the pedal will "feel" different and cause a slight miss if the diaphragm is punctured when brake pedal is depressed.

If driving daily with drums they need monthly adjustment to keep the brakes in good working order, well in my experience any way.

Devilrod · Post by **Devilrod** » Wed Jun 25, 2008 12:44 pm

Better ask as I forgot to do you have drums all round if so see my post above, should do the trick.

Sammy · Post by **Sammy** » Wed Jun 25, 2008 1:21 pm

from what you've described i reckon the first pump of the brakes is priming them and getting the pads/shoes right up to the brake surface and then the oil is not bleeding out in time and so when you press the pedal the second time it requires less fluid to move before the brakes start applying.

very similar to what you see the v8 supercar boys doing at the end of a big straight, they pump the pedal while they are still accelerating to make sure the pads are as close to the disc as possible, then when they stand on the brakes a few seconds later they get maximum brakes without the pedal going down to far or having one pad further away from a disc than the other side etc....

having said this your problem might be that a line is partially blocked with a build up of crap and hense is not letting the fluid bleed back to the master cylinder as quickly as it should .... but generally it sounds like what is happening is the same thing that people who actually do have leaking brakes will do which is the pump the pedal to get the fluid up and have the pedal right up then brake so the pedal doesn't go to the floor!

Brown Bear · Post by **Brown Bear** » Thu Jun 26, 2008 8:35 am

Thanks guys!

This has been a niggling issue for a while now, and as I'm working on some steering issues I thought it would be best to address the brakes as well.

I took the front drums off last night and everything looks OK at a glance - no fluid leaks, worn linings or scored drums - so perhaps a flush of the brake lines might be the thing to do.

Cheers,

Matt

karsten · Post by **karsten** » Thu Jun 26, 2008 7:57 pm

if when you put your foot on brake does the pedal slowly sink to the foor if so then thats oil bypassing the plunger in the master cylinder put a kit through it and fresh fluid ,,get it honed to make sure its cylinder is smooth and clean,,, this can happen without leaking ,try it under hard and soft application on the brake,, if the pedal is not sinking make sure yoe ajust them jacked up so there just not sraping and that mite also cause the pedal to need a pump cause the master doesnt push enough oil in the first pump cause of exsesive brake shoe,, drum gap

FB MAD · Post by **FB MAD** » Thu Jun 26, 2008 8:20 pm

Matt,

When you say "ratchet up", do you mean that on braking, the pedal sort of "pulsates" or goes up and down very slightly with your foot on the pedal ??

If so, your drums may be out of round and need machining.My old bomb does it ATM and it is a pain in the....well.....you know............Bum

I'm too lazy right now to take 'em off and have 'em machined

Brown Bear · Post by **Brown Bear** » Fri Jun 27, 2008 7:27 am

I mean that the pedal is at one height when the brakes are first applied, then higher on the next application. Usually the pedal height is consistent

FB MAD · Post by **FB MAD** » Fri Jun 27, 2008 9:38 am

Ok, it's not what I've just written above then

FB MAD · Post by **FB MAD** » Fri Jun 27, 2008 9:45 am

Are you sort of like "pumping" the brakes when you apply them??.Or fairly quick application of the brakes??.If so, you can get different pedal heights when doing this at times especially if brakes need adjusting.

I get different pedal heights in mine ATM when the brakes are pumped or on quick repetitive application,although I'm not running a booster like you are.

I think others above have said it above

but try adjusting your brakes.Will explain the reason if you want as to why you have to pump the brakes up when they need adjusting but don't want to make it too confusing as it gets into hydraulics and such and would get into a lengthy reply especially the way I describe things

Mine need adjusting ATM since the Yamba trip and I'm getting similar things happening.Brake adjustment will fix it.

It's just too bloody cold and I'm in lazy mode ATM to do it!!

karsten · Post by **karsten** » Fri Jun 27, 2008 10:28 am

yeah id bet, fb mads,,left ball its in need of a good ajustment,,

sorry mate i thought it was safer to bet with your balls not mine

ooouuuuccchh!!!

FB MAD · Post by **FB MAD** » Fri Jun 27, 2008 1:01 pm

But....but....but....me left one's me favourite

autobilly · Post by **autobilly** » Tue Sep 02, 2008 2:02 pm

[quote="Brown Bear"]
...I took the front drums off last night and everything looks OK at a glance - no fluid leaks, worn linings or scored drums - so perhaps a flush of the brake lines might be the thing to do.

Cheers,

Matt[/quote]
If all is good as you say and the shoes were radiused to the drums, a fluid flush won't hurt (recomend every two years), but ajustment is what you need.

Brown Bear · Post by **Brown Bear** » Tue Sep 30, 2008 8:52 am

I believe this one has been solved

Seems it may be the same problem which causes the brake pedal to gradually sink to the floor while resting your foot on it at the lights

No fluid loss is evident, so I believe a master cylinder change out will be on the cards in the near future, along with some new fluid and an adjustment

Sammy · Post by **Sammy** » Tue Sep 30, 2008 1:48 pm

internal oil leak by the sounds of it!