Fluid dissapearing

stina

stina

New Member
Hi Guys .
Noticed over the last few months that the fluid level has dropped in the reservoir . I have done the rear calipers in Nov 2011 , didn't have the money to sleeve them in stainless as is the fashion so just resealed them until funds permit .
Anyhoo , i thought that time had come as the fluid level dropped , however looking underneath around the calipers it's totally dry , so i looked in the other places that we all know the fluid likes to visit every now and then :D Carpets under brake pedal , dry . Front calipers , dry . But on pulling out the air valve from the servo , found it :D
So the question . How best to tackle this one , do i just get a seal kit for the servo , or totally overhaul the servo while it's off , or do i need a new one ( perish the thought :shock: )
Is it doable for the DIYer ?
Thanks in advance .
 
Hi Stina

Had the same problem last year on my 2200TC. It tells you in the Haynes manual how to rebuild the servo if you want to do it.

At the time the car was running like a pig and I had the cylinder head off so had enough on, I decided to have it rebuilt professionally. The company I used is actually local to me but was recommended to me by another supplier down south. Apparently they rebuild most of the servos in the country either directly or indirectly.

Here is their website http://www.jlspares.com/ cost I think about £140. The servo on my car was in a right state when I dropped it off..

...and here is a picture of the reconditioned unit on the car download/file.php?id=6277

Hope this helps.
 
Hi Pat ,
That looks tidy under the bonnet . Thanks for the link , i will contact them if i need a new / recon servo . Hoping someone comes back telling me i can reseal / rebuild it my self though and save a few quid , still recovering from re building the auto box :roll:
 
however looking underneath around the calipers it's totally dry
Click to expand...
It may well be dry around the calipers yet soaking wet inside the metal covers

Whether you can do a DIY rebuild on your servo depends on what state it's in when you strip it down, Fitting new seals should be a piece of cake if you can do autoboxes
 
Hi Stina,

I've rebuilt two or three dual and single circuit servos in the past and can say that it's messy but straightforward enough unless you find significant pitting in the bore. If light, you could deal with it using a honing extension on a drill, or have someone do it for you. Some forumites have mentioned sleeving the servo cylinder when they get very rusty. A vise is handy when undoing the fluid inlet and outlet. I seem to remember there's also a piston stop pin under the inlet that could get lost easily.

You could be lucky and find your issue is a dud valve piston seal and that the fluid coming out of the cylinder itself isn't full of rust. Good luck!
 
Hi Stina,

If you're in luck, the slave cylinder including the bore of the air control piston, will have already been resleeved. Given it's age that would certainly seem likely. The boosters (servos) were manufactured by both Girling and Lockheed with the notable difference being the way in which the two halves of the vacuum chamber are joined. If you're in luck you'll have the Lockheed as it will have a separate band that retains the two sections together.

Apart from the large diaphragm within the vacuum chamber, which you should not need to replace, the piston rubbers are the only items which usually require replacing. If however there is corrosion along the length of the pushrod, you will need to source a replacement else the rear seal that prevents fluid from entering the vacuum chamber will be damaged. I seem to recall that these are available in stainless steel from booster specialists that specialise in classics.

Ron.
 
Thanks for the replies guys .
lots of information there .
I guess to be sure of an easy job i'd go for a recon unit and swap it over between cups of tea on a Saturday morning .
Or to try to save a pound or two i'd order a seal kit and hope the piston and bores are servisable .
That looks like the way i'll go , any more advice welcome .
 
The usual scenario Stina is that you need to give them your booster before they will exchange you a reconditioned unit. A rather large additional non refundable fee usually applies otherwise.

A complete booster seal kit which are very hard to come would typically set you back around 60 Pounds or more, which if the bores need resleeving would be only a fraction of the total cost.

If you can obtain a ready to fit exchange booster for 140 Pounds, then that is the safest and possibly least expensive option.

Ron.
 
See where your coming from Ron . Guess it's up to me to search out the options and make a decision . At least this is one that doesn't involve groveling around under the car :D ( bleeding aside , but i'll send one of my minnions under it for that :LOL:
 
I got a seal kit for my servo and done it, not too bad as mine was not pitted and in good nick, as I was doing the brake and clutch seals just thought I would do them all. I'm sure you will enjoy it :D
 
Thanks Mick . Think i'll order up the parts tomorrow , and have a crack . :D Gotta be worth a go before wacking out loads of money .
 
Hope that the seal kit (and maybe honing) does the trick Stina.

I wondered about honing something like this. I have seen at least two types of tool used - the kind that Stina is looking at and the "toilet brush" kind as per the link:
http://www.brushresearch.com/flex-hone-sizes.php

I wondered if anyone has experience of both and what are the pros and cons?
 
O.k jvy , that sent me on an ebay search for honing brushes , their are loads of them in different sizes . Does anyone out there happen to know the size of the bore in the servo ?
 
DaveHerns said:
Does honing the bore remove any plating/finish that means it then corrodes faster ?
Click to expand...

If it's pitted / corroded then i guess were past worrying about that Dave ! Don't really want a debate , just the bore size if anyone can help ?
 
Hi Stina,

Why worry about honing brushes when you may not need them? Master, slave and rear caliper cylinders were corroding away way back in the 1980s. Even NOS items can corrode and require resleeving just sitting in the box. More likely than not the slave cylinder will have already been resleeved in stainless steel in which case you don't need to touch it. Just fit the new seal kit and you're done.

If a bore has not been resleeved and you start honing away to remove the pit corrosion, the inside diameter of the bore increases so there is greater clearance between the piston, seals and bore. End result is less than satisfactory performance from the seals in terms of working life whilst the bore happily starts corroding again due the brake fluid being hydroscopic, hence the need to change it all every 18 months to 2 years maximum regardless of how little the car may be driven.

When cylinders are resleeved the original bore is enlarged and the sleeve inserted, thus the internal diameter is the same as when the cylinder was brand new. This keeps everything in terms of clearance exactly where it should be.

Sorry if I seem a little terse, but logic needs to prevail.

Ron.
 
Hi Stina,

I've not got a cylinder to hand nor the bore size but that tool looks very similar to mine and at that price I'd be inclined to say that it'll work. The bore is surely not smaller than 19 mm.

I'd imagine they'd stock the tool at Halford's so you might not need to pre-emptively buy it?

The bore is raw metal, with no surface treatment to spoil.

Tor
 
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