BJ8 Blake Bleed Mystery - Low Fluid Flow

[Andrew1]

Hi Everyone, had an interesting stopping experience today while traveling at 70 mph with a need for a quick stop. The brakes activated and the car swirved right as a result of poor braking on the front left disc brake.

I un tightened the brake bleed screw to test the brake fluid flow rate. There continued to be extreme resistance, and low fluid flow rate out of the bleed screw. This is compared with my brake bleeding experience on the remaining three wheels.

As a check, I removed the small steel brake line running to the caliper to observe the brake fluid flow rate befor the caliper. This checked out fine with lots of fluid flow.

Can someone suggest, what might be causing or a fix to the unusual flow resistance in the caliper?

Cheers!

- Andrew - /ubbthreads/images/graemlins/shocked.gif

 

[Keoke]

HI Andrew, It might be that the bleed screw is just cruded up or if its the original style the little ball inside may be rusty and also need cleaning up. Using two drills of the appropriate size clean the holes in the bleed screw out and blow clear with compressed air.Of course you could replace it with new--Fwiw---Keoke

 

[Andrew1]

Fixed.

It required the disassembly and removal of the caliper. In this case the inboard piston seemed to be jammed. Upon removal, I found light pitting on the piston which cleaned up fine.

With the piston stuck closed, there seemed to be rubber crud blocking the valve hole that goes to the bleed screw. I think I'm going to buy one of those vaccuum bleeder devices. No body to help me today!

- Andrew -

 

[Keoke]

Well Andrew, I said it "MIGHT "be, Seriously, though if the rubber seal on the piston was not chewed up I would have a look at the rubber hose that feeds that caliper it just MIGHT be damaged on the inside. Glad you got the problem sorted out---Keoke