Bleeding Brakes!

[se9boy]

Hi,

I'm looking for some advice / pointers please. My car has been off the road for 5+ years now and I'm in the process of trying to get it up and running again. After sorting a leaking clutch slave cylinder my attention has turned to the brakes. I've freed off the front brakes and they seem ok (the calipers were new / reconditioned not long before the lay-up), I've rebuilt the nearside rear cylinder and fitted a new cylinder to the offside (both are 0.75" bore) along with a set of new brake shoes.

Now I'm struggling to bleed the system through. I have a vacuum pump, which I thought would make it an easy job, but I seem to be getting nowhere. With the pump set up and the bleed nipple open the nearside effectively holds the negative pressure with no movement (no air or fluid apparent). The offside is drawing air through easily but after half an hour or so I got no more than a teaspoon of fluid through - I'm fairly sure the air is not being sucked in through the bleed nipple thread, in fact I think I can hear a feint bubbling from the front of the car which I initially thought was from the brake fluid reservoir but can't be sure - it's difficult to pin point as I'm trying to do the job on my own.

I'd greatly appreciate some advice on what to check next.

Many thanks, Steve.

[heightswitch]

Your brake pipes and pretty much everything else will be resembling tarred up treacle.

You need to replace all your brake lines, strip down your callipers, likely as not renew all of your cylinders and any perished rubbers. When all of your braking system is comprehensively renewed then try bleeding thm again.

If you are trying to do this to a std vixen, likely as not you will also find that the brake failure warning light device is also cruddy and seized.

N.

[se9boy]

Many thanks, this makes sense.

I was hoping the fluid would not have turned to 'sludge' whilst the car has been laid up - time to invest in some more parts!

Steve.

[chassyman]

hi steve, just a thought for you, unscrew the bleed nipples completely and make sure they are not clogged up, it,s not uncommon. also when bleeding with the pedal don't press it more than half way down because it's going where it hasn't been before and can cause you a lot of bother!!!! best regards keith

[se9boy]

Thanks for the note. I've had the bleed nipples completely out (+ one of the cylinders is new) and made sure they're not blocked, checked both of the rear cylinders for leaks and made sure the fronts are not leaking - there are no visible leaks from pipes (or on the garage floor). My car ('77 3000M) has the brake set up with a PWDA valve, I've been reading up on the problems associated with this and am planning on removing the warning switch to check on the position of the valve and its operation before I go too much further. Also going to replace the rear hoses as they're probably well past their sell by date.

Steve

Edited by se9boy on Friday 5th July 21:27