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Brakes needing 2 pumps ????????
Posted: Sat Feb 21, 2009 1:00 pm
by Swerve
Ok the problem was the brakes would need 2 pumps for the pedal to be firm.
I So the issue is 2 pumps for a firm pedal, I was hoping I just had air in the lines :( which after bleeding all four wheels no change.
Just took the Brake M/C out and the cylinder looks perfect, rubber rings on the dual stage pump look fine ???
All the rubbers have a nice sharp edge with no tears or nics ?
So QUESTION
What is the typical cause requiring you to pump your brake pedal 2 or so to have a firm pedal ???
No fluid leaking at the MC. Havnt taken wheels off to check wheel cylinders, but if they were leaking I still wouldnt have this issue!
So change the rubbers and pray ??
Posted: Sat Feb 21, 2009 1:20 pm
by Tiny
had some problems recently with my uncles triton. had some air in the lines so bled, better but spongly, noticed there was some leakage around the master so changed it out and a bit better but still spongy and needed a couple of pumps to firm up properly. wasnt to bad, but more annoying than anything was about to look further into it when the alternator died in the arse, put a new one on (oiler with vac unit on the back of the alt) which fixed the brakes right up so I would suggest thats worth a look, vac pump if it is that style or vac lines etc
Posted: Sat Feb 21, 2009 1:23 pm
by thomo
Warped disc that pushes the pads back ? Unless its 4 wheel drums
Posted: Sat Feb 21, 2009 1:27 pm
by Swerve
Sorry it is 4 wheel drums !!
I have the same issue with the engine off so it rules out the vacum pump or whatever you call the bif black thing
Hmm, just thinking I should have checked the brake pads clearance on the drum,
Posted: Sat Feb 21, 2009 1:40 pm
by Utemad
What about swelling rubber brake hoses?
I recently fitted braided hoses on my Disco and the pedal got a lot harder.
I never needed two pumps but the pedal was a lot softer than I'd have liked.
Disco's have discs all round but shouldn't differ much in operation really.
If you are not visibly leaking fluid then I'd think it has to be either swelling hoses, air in the lines or stuffed master cylinder.
Posted: Sat Feb 21, 2009 1:40 pm
by Tiny
Swerve wrote:Sorry it is 4 wheel drums !!
I have the same issue with the engine off so it rules out the vacum pump or whatever you call the bif black thing
Hmm, just thinking I should have checked the brake pads clearance on the drum,
yeah ok then, with 4 drums as you have figured out, it is probably the clearence of the shoes on the drum
Posted: Sat Feb 21, 2009 2:48 pm
by Swerve
Just back from lunch and will check the drag (or probally no drag) on the wheels before re-installing it.
Posted: Sat Feb 21, 2009 4:15 pm
by hudson44
the drums will need to be removed and adjust the shoes.
Posted: Sat Feb 21, 2009 5:40 pm
by Swerve
Not on the G60, have bolts on the back of the drum !! easy just jack wheel up and adjust.
Well front left was heavily out, reinstalled Brake master, rebleed system and same f'ing issue.
I'm certain it's the rubber o'ring in the brake master, will either buy a kit or a new brake master !. Depends how I feel on Monday.
Just over the peice of crap right now
Posted: Sat Feb 21, 2009 5:48 pm
by 11_evl
i would of thought 2 pumps on a 4 drum car was acceptable, if not bloody good.
obviously it was better and something has made it go bad.
to me it sounds like shoe adjustment
Posted: Sat Feb 21, 2009 5:52 pm
by Swerve
On my other G60's they work as good as disc !!
All drums are very slightly dragging so its not drum alignment.
$10 bucks its the master , wait till next week when I change it !
Posted: Sat Feb 21, 2009 6:25 pm
by 11_evl
after 2 pumps is it a solid pedel that doesnt sink when pressure is applied??
Posted: Sat Feb 21, 2009 9:23 pm
by Wilba
Not sure of the set up on g60 but just check you haven`t got somthing simple like dodgey wheel bearing movement. can cause the drum/ disk to press slaves together needing more pumps to get them closer to grab. might help.
Posted: Sat Feb 21, 2009 10:19 pm
by Swerve
11_evl wrote:after 2 pumps is it a solid pedel that doesnt sink when pressure is applied??
correct.
If I then take my foot of the pedal for 10 seconds and re-apply I need 2 pumps again.
Posted: Sun Feb 22, 2009 4:14 am
by zagan
Should have a master cyclinder to start the build up of pressure and a booster to mainly hold or add to the pressure.
Supposed to have full pressure once the brake pedal is about a quater of the full pedal arc.
I have the same problem I'm not sure what causes it though I went I did a pad change the pedal did firm up a bit better, pedal might need adjusting.
who knows.
Posted: Sun Feb 22, 2009 10:19 am
by roblrc
Do the easy things first adjust the brakes. What you describe are classic symptoms of poorly adjusted brakes. Never pull anything apart if no visible signs of leaks till you have adjusted the brakes. Why create problems for yourself without doing the basics first.
Posted: Sun Feb 22, 2009 10:23 am
by roblrc
Swerve wrote:11_evl wrote:after 2 pumps is it a solid pedel that doesnt sink when pressure is applied??
correct.
If I then take my foot of the pedal for 10 seconds and re-apply I need 2 pumps again.
Fluid bleeds back slowly after releasing pedal, first pump pushes shoes out to contact drum then on second pump pressure builds as shoes already out then will hold till pedal released
Posted: Sun Feb 22, 2009 10:30 am
by roblrc
Swerve wrote:On my other G60's they work as good as disc !!
All drums are very slightly dragging so its not drum alignment.
How much lining is left are the shoes aligned properly, different than adjustment, only a small contact area will create drag but will not be adjusted properly
$10 bucks its the master , wait till next week when I change it !
Posted: Sun Feb 22, 2009 11:08 am
by shrekman
A quick way to isolate it is to clamp each of the flexible lines. Use proper hose clamp pliers it you have (or can get) them or very gently use vice grips. Do all the flexible lines and see if the pedal goes (and stays) hard. If after clamping them all off and the pedal is solid then the problem is not in the master cylinder. Then just release one line at a time to locate where the problem is.
Dave