Leaking Wheel Cylinder

[crankin]

I have a new front and rear rebuild kit form AB...to go along with my new brake MC and brake lines. After I bench bleed the MC and all four brakes...after driving a bit and applying the brakes i lose pressure. SO, i went back to the house and check. The rear left tire is covered in dot3. Checked the bleeder valve and everything is tight. Removed the brake drum and the wheel cylinder is leaking.

I would think that its a faulty wheel cylinder...but this is the second one. The first one did the same thing. Whats going here? The other three are fine... just the rear left wheel cylinder.

[jac04]

Since the wheel cylinders are specific to each corner, I would say that you got 2 cylinders from a bad LH Rear batch - maybe the bores were machined too big.

[crankin]

OK. I can handle that...seeing how AB replaced the first one for free. Could there have been anything that I would have done that would have caused this? It is pretty straight forward and simple to install these....but you never now.

[scott]

could it be that the drum has been turned until it's now out of specs? if the id of the drum is to great won't the wheel cylinder travel to far?

[crankin]

They are new drums. And i have turned the spacing until it jsut touches the drums

[4flattires]

crankin, you may want to call AB and see if they have had issues with this part. It's easy enough to research with them, and they can with their vendor as well.



could it be that the drum has been turned until it's now out of specs? if the id of the drum is to great won't the wheel cylinder travel to far?

Scott, good thought, but highly doubtful. Even if you turned the drum waaaaaayyyyy over the limit, (say going to .180" vs .060" over) there is far too much wheel cylinder piston left in the w/cyl to allow the cup to get cock-eyed and leak.

My vote is for a bad batch on something with a low production rate as this wheel cylinder.

[bkreutz]

I'm inclined to think it's a part issue, seeing that you had no problems with the install method on the other wheels, can't imagine you'd do something "wrong" on the affected wheel. :)

[Sputnicker]

"I have a new front and rear rebuild kit form AB"

Sometimes a rebuild kit is not enough and you need a new wheel cylinder.

[siii8873]

I agree w/ sputnicker. I tried to rebuild a master cyl but the bore was in to bad condition and leaked after the rebuild. Assuming this cyl was rebuilt and not new. If new probably a bad part, not rocket science to install these.

[SafeAirOne]

Sometimes a rebuild kit is not enough and you need a new wheel cylinder.

I concur.

Also, did you say you were using DOT 3 brake fluid? I'd have used the Castrol LMA (available at PepBoys) that is recommended for series rover brake and clutch systems. There is debate as to whether there is any natural rubber left in rover brake and clutch systems nowdays, but you can roll the dice and use DOT 3 which may or may not destroy your rubber components or you can be safe and just use the Castrol LMA as recommended by the factory.

[greenmeanie]

Who manufactured the kit? If it had Britpart on the label then I'll bet that is your problem right there. Their seals are notoriously poor quality.

[crankin]

Its not a rebuilt kit for wheel cylinders...it was new parts to rebuild the whole brake system. And I will second the britpart stuff...i have had the worst luck with them. The wheel cylinders are from another company though...

I'll call tomorrow and see what they say.

[crankin]

New one is coming in the mail. We'll see what happens.

[Andrew IIA]

I concur.

Also, did you say you were using DOT 3 brake fluid? I'd have used the Castrol LMA (available at PepBoys) that is recommended for series rover brake and clutch systems. There is debate as to whether there is any natural rubber left in rover brake and clutch systems nowdays, but you can roll the dice and use DOT 3 which may or may not destroy your rubber components or you can be safe and just use the Castrol LMA as recommended by the factory.
I confess little knowledge of brake fluid specs, but my SIII manual specs DOT 3 as the proper stuff, so that's what I've been using.

ps. my SIIA has an SIII brake system.

[SafeAirOne]

...my SIII manual specs DOT 3 as the proper stuff, so that's what I've been using.

ps. my SIIA has an SIII brake system.


Hmmm....

[thixon]

Are you POSITIVE its the wheel cylinder itself thats leaking? Could it be leaking at the fitting, or the line instead? maybe you cracked the line or tore up the fitting when you removed the old cylinder. Sometimes its hard to identify the source of a hydraulic leak.

[crankin]

It was actually coming from the left hand cylinder around the rubber seal. I could see it forming a drip.

When I called and spoke with someone from AB that really didn't seem surprised and promptly responded that they will ship another one out that these things happen sometimes. I actually asked to be refunded that amount so that I could buy a Girling, so they placed me on hold, came back and said that they had a Girling in stock and would swap it out for me…free of charge.

I would think that it could be a torn fitting or a cracked line. However, these are all brand new and made their first maiden voyage on the new wheel cylinder. So, I am still thinking that it’s a bad batch and a bad part.
I should be getting it in this week. And if all goes well should be able to give some more feedback.

[crankin]

Feel like i should give some feedback now. After three after market cylinders (all from the same vendor and all leaking), I asked to be sent a Girling one.

I had became so fast at installing the wheel cylinder that I did it in about 15 minutes and had it on the road. All is well and no more leaks.