• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Rear wheel cylinders over extending ??WHY?? Making a mess fluid everywhere!!!

Share this page

Here are Pictures of my Brakes. The First is the passenger side disassembeled and the second is the drivers side assembled.

PC310409_zpsc73952f2.jpg


PC310407_zps93075552.jpg
 
Take a piston out of the cylinder and see if the seal is fitted the right way round. The lip of the seal should go down the hole first and be slightly difficult to get started in the bore
 
Does your rubber dust seal have a circular retaining clamp/clip (note steel retaining clip on GregW's pic) holding it in place. Your's looks all black. Is there a black clip?
Can you lock the brakes with the adjuster? The brake friction material looks thin for new brake shoes. Does the locking clip on the backside of the backing plate allow the brake cylinder to slide back and forth as it should?
 
I pulled out wheel cylinder piston and seals are installed correctly. Now I am looking @ the parking brake assembly.I notice my cable seems to be su\tuck. I am wondering if it is creating to large a space between the brake shoe and the piston on cylinder ??? What do you think ??
 
I don't think so, at least on the driver's side you show above. The other side looks problematic. Do both seals pop out, or just the passenger side? Does the brake shoe fit deeply into the piston slot on the passenger side as it appears to do on the driver's side? If the passenger side didn't fit in the slot, it would be hard to get the drum back on if you have the right brake shoes.
 
Try measuring the circumference of the assembled brake shoes and comparing that with the inside circumference of the brake drum. They should be very close
 
Jeffsbj8 said:
Here are Pictures of my Brakes. The First is the passenger side disassembeled and the second is the drivers side assembled.

PC310409_zpsc73952f2.jpg


PC310407_zps93075552.jpg
Click to expand...
The material on your shoes looks awfull "thin", but it still should adjust properly.
 
well... I'm stumped now. I can't believe the pistons are pushing all the way out of the bores as it is pretty much impossible to expand the shoes that much with the drum on and your pics show everything fitted up ok.

Do you have any way of clamping the wheel cylinders so they can't extend and applying the brake pedal to see if the cylinders are faulty? Maybe porous castings or something?
 
Patrick67BJ8 said:
The material on your shoes looks awfull "thin", but it still should adjust properly.
Click to expand...

Judging from the paint, these appear to be the same replacement shoes I bought when I did the brakes on my BJ7 and the friction material is noticeably thinner than an original shoe. I couldn't get them to adjust out far enough to grab the drums. I didn't have a problem with the pistons coming out of the cylinders, though.
 
First thank you all for all the great advice. IT SEEMS YES THE SHOES THICKNESS IS MUCH NARROWER THAN ORIGINAL. IN THE PAST WHEN I INSTALLED NEW PARTS ( 1)WOULD BLEED BRAKES (2) ADJUST BRAKES. WELL WITH THESE SMALLER SHOES IT SEEMS WITHOUT ADJUSTING BRAKES FIRST TO PUSH OUT THE SHOES IT STANDS A CHANCE OF OVER EXTENDING PISTONS ON THE CYLINDERS. THIS AFTERNOON I WENT OUT TO MY GARAGE PUT EVERYTHING BACK TOGEATHER AND RAN ADJUSTER IN UNTILL THE BRAKES LOCKED UP , JUST AS SOME OF YOU SUGGESTED, THEN I GOT MY SON TO PUMP THE BRAKES , JUST LIKE DURING A PANIC STOP AND BINGO EVERYTHING SEEMS FINE.I NEVER HAD SUCH A SMALL JOB BE SUCH A PAIN. ONCE AGAIN THANK YOU ALL HAPPY NEW YEAR & GOD BLESS, JEFF PS LET THIS BRAKE PROBLEM BE A CAUTION TO US HEALEY GUYS!!!
 
Thanks for the feedback, sorry for your troubles.
 
Thank you very much, just a couple of things , my brake drums are original, the shoes are Power Tune and the cylinders are aftermarket(Taiwan)
 
Glad you got it sorted but it does seem odd and perhaps a little dangerous that having the shoes unadjusted could cause complete hydraulic system failure. Not sure I'd be very comfortable driving with that.

Andy.
 
Jeffsbj8 said:
First thank you all for all the great advice. IT SEEMS YES THE SHOES THICKNESS IS MUCH NARROWER THAN ORIGINAL. IN THE PAST WHEN I INSTALLED NEW PARTS ( 1)WOULD BLEED BRAKES (2) ADJUST BRAKES. WELL WITH THESE SMALLER SHOES IT SEEMS WITHOUT ADJUSTING BRAKES FIRST TO PUSH OUT THE SHOES IT STANDS A CHANCE OF OVER EXTENDING PISTONS ON THE CYLINDERS. THIS AFTERNOON I WENT OUT TO MY GARAGE PUT EVERYTHING BACK TOGEATHER AND RAN ADJUSTER IN UNTILL THE BRAKES LOCKED UP , JUST AS SOME OF YOU SUGGESTED, THEN I GOT MY SON TO PUMP THE BRAKES , JUST LIKE DURING A PANIC STOP AND BINGO EVERYTHING SEEMS FINE.I NEVER HAD SUCH A SMALL JOB BE SUCH A PAIN. ONCE AGAIN THANK YOU ALL HAPPY NEW YEAR & GOD BLESS, JEFF PS LET THIS BRAKE PROBLEM BE A CAUTION TO US HEALEY GUYS!!!
Click to expand...
Refer to post #2 ;)

Glad you got it sorted out, but to me, it's more natural to complete all the mechanical tasks, including physical adjustment, before moving on to the wet work__bleeding the circuits.
 
Back
Top