Brakes bind up after a while

[VBRED]

Just sorting out a few issues.

My main issue is that after 10 minutes or so the brakes gradually come on and the pedal becomes harder and harder. You can feel that the car does not want to roll freely. All 4 wheels are hot.

If I leave it for 10 minutes or so the problem fixes itself. My vb is running VN V8 disc brake set up with a 1" master and V8 booster.

Is this a stuffed booster?

Pete

[Sabbath']

How long ago did you last change the brakefluid?

If there is high water content, it lowers the boiling point of the fluid,causing decreased pedal performance.

Also moisture could be causing premature rusting of some components.

[VBRED]

The car has been rebuilt. Bleed the brakes all new fluid 3 days ago.

[ari666]

my booster did the opposite when it died. started leaking vac on braking and had no suck, so you had to use both feet to get her to stop suddenley. i cant imagine why they would 'pull' on your brakes.

so all 4 wheels do it? it wouldnt be one wheel with a stuffed piston? creating too much pressure on the other 3?

[VBRED]

Could be I will check the rear calipers for a start. The rear diff sat around for a while before I installed it. Was not too sure where to start.

[strgas]

Check the brake pedal pushrod for free play , and the booster rod for free play ???

[Tree cutter]

I would say it doesn't have enough pedal freeplay so the brakes aren't releasing fully.

[ScoHar]

Check those rear calipers, they have a tendency to seize.

[ari666]

Check those rear calipers, they have a tendency to seize.

i 2nd that. thus putting too much pressure onto the fronts and causing them to engage.

[ScoHar]

i 2nd that. thus putting too much pressure onto the fronts and causing them to engage.

especially if you've just fitted new pads also

[MICKY.D]

Ive seen this on a VT R8 clubby, friend of mine had her brakes done and fluid changed, then a few days later she rang and said her car had lost power (supercharged LS1) and had a hard peddle after driving for 10 mins, it ended up being the brand new fluid was contaminated and caused all the rubbers to swell once warm??? weird.... but it killed every rubber in the braking system cost her $$$, The brake place didnt help her one little bit the bastards!!! once all rubbers changed and new fluid was good as new... might be something to look at, maybe just pull one caliper off or look at master cylinder piston rubbers see what it looks like???

Cheers
Mike
YT

[VBRED]

I am rebleeding the brakes with a different fluid to start with in case it has water or air in the system. I will check all the calipers to ensure that they are not binding.

I suspect that it is not a simple answer like that.

[Not_An_Abba_Fan]

I'd be checking the valve that the hose connects to on the booster. If it is stuck open, it will have constant vacuum pulling on the booster, engaging the brakes.

[VBRED]

I think it must be booster or master cylinder related.

After I bled the brakes again and check the operation of the calipers I was going to disconnect the booster vacuum line and see if the problem continues to happen. If it continues to happen i think it would have to be an issue with the master cylinder.

[immortality]

I'd be checking the valve that the hose connects to on the booster. If it is stuck open, it will have constant vacuum pulling on the booster, engaging the brakes.

thats only a one way valve, that way the booster maintians vacuum when you have no vacuum in the intake manifold. hence the reason the vac assist (for 1 or 2 pumps of the brake pedal) still works with the engine off.

MICKY.D's answer sound logical but the most expensive.

i'd strip one rear caliper and check the condition of the rubber seals.