Brake servo

[davidwheeler]

Ah, but it was not so.  They continued to bind and I had to slacken off to an absurd degree and never seemed to be able to get the sponge out of the system.   Finally I looked at the front brake pads.  I took them out and the pads (scarcely worn) promptly fell off their backing plates!   I have skimmed the discs and fitted new pads and the brakes at last feel as they should and I have been able to lengthen the operating rod back to where it should be.  'Tis what happens when the car has been off the road for a bit I suppose or maybe they got pulled off in a binding on episode.   Whatever, there is always something to surprise us.

[nistri]

Do you know the make of these pads? Andrea

[davidwheeler]

Not off hand, they came from Omicron but have been in place a number of years.    I guess they got damp.

[phil-m]

I would not be so generous, even if they got damp and had been stood the pads should not have seperated from the backplate.

[ben]

Further to Neils comment that overhauling the servo is not too difficult this is the special tooling I have just used to get mine apart.

[ben]

Also while on the subject does anybody know if the banjo connection to the vacuum chamber is supposed to be a one-way valve.
Mine was completely blocked which would obviously mean the servo wasn't doing much. It also explained why there was a large quantity of brake fluid trapped in the servo vacuum chamber which would normally get sucked into the engine. The rubber diaphragm was in good condition so I have re-used it.
I have cleaned out the connection which seems to have quite a devious baffle inside it but it now appears to be able to flow in either direction.

Incidentally I found the overhaul of the master-cylinder to be a more challenging undertaking.
The screws retaining the reservoir were very reluctant to come out. Three of them sheared off !
Then the big plug in the end of the body required the application of heat to the alloy body before it would come undone.(32mm spanner and 3 foot lever arm!!!)
Also note, when reassembling feed all the bits in from the plug end to minimise the chance of damaging the nice new seals that Omicron supply.And don't forget the aluminium washer that the plug seats down on. 

Next job is to attack the calipers!

[JohnMillham]

Is there a simple way to reduce the size of the photographs, so I can see the whole photo in stead of just one corner of it?
Regards, John

[davidwheeler]

Use this program
http://www.obviousidea.com/windows-software/light-image-resizer/
David

[davidwheeler]

And yes, it is a one way valve and if it is blocked the servo does not work.   The object is to accumulate vacuum in the chamber, if the valve does not work vacuum is lost when you accelerate.   If your is now two way you will need to replace it.

[ben]

Just as I suspected.I will now have to see if I can get that apart!

I don't know why the pictures came up oversized John.
On my PC you can click on the blue titles at the bottom of each picture which gives you a box at the bottom of the screen on which to click again and they then appear at the correct size

[lancialulu]

I flushed mine out and after a while it seemed to work so I put it on the car 7 years later it still is working....Difficult to open up as a peened over assy??

[ben]

Even after an overnight soak and much blowing and squirting  I was not happy with it so bit the bullet and opened it up.
The alloy was too brittle to "unpeen" so I filed away the peened over bit and have exposed the innards which I can now clean properly. It was full of a dried out brown deposit which presumably is a residue from brake fluid. (The car has not run for about 20 years)
I think it should hold back together with a little araldite and a small clamping ring.

Hopefully the picture of the innards will be the proper size this time!       

[lancialulu]

Another bit of beautiful engineering!!

Photo still large on forum though.....(it is fine if clicking on the blue file name)