Brake Servo for series 2 V8

P

prospect8816

Member
Hi,
Anybody know where I can get a replacement Brake Servo for my 1974 P6B 3500 V8 Auto. According to the Haynes workshop manual, the one I require, is a "Girling Type 8".

I have made an enquiry re Geoff @ Wins, but he is quoting £175.00 + VAT (Exchange) P&P £10.95 + VAT. A surcharge of £40.00 + VAT will apply, which is refunded when the old servo is returned. All in all, a bit pricey. So if any member can tell me where I can find one cheaper, I would be obliged!

Paul :shock:
 
Sorry Paul, that's a very reasonable trade price. If the only problem with yours is seals why not overhaul your own? Seal kits (including the large air diaphragm) will be around £30 to £50, again most likely from Wynn's or JRW. You may be unlucky and also need the white plastic air valve on the front of the casing, which would be about the same again. The Wynn's price starts to become really attractive if you need the hydraulic cylinder within bored and sleeved.

You might be lucky and pick up either seal kits or a complete servo from Ebay. But be aware that complete servos are rarely in working order once they have been off the car for a month or two!

Are you sure that the servo is your problem? The symptoms can be difficult to diagnose. What is yours doing?

Chris
 
Hi Paul,

Here in Australia most brake places want something like $500 for a reconditioned booster (servo) , that is like 340 Pounds, so as Chris said, what you have been quoted is extremely reasonable. Also following on from what Chris said, quite often they charge a blanket rate irrespective of what actually needs doing to repair yours. As my slave cylinder had already been resleeved back in the 1980s there was little point in forking out large sums of money when all I needed was a few seals, so I bought some seal kits and overhaul them myself.

Ron.
 
To Chris York. In answer to your query.

Hi Chris, Last Saturday week after I had taken the car from the garage, I was checking the usual fluids, engine oil/transmission but when I looked at the brake reservoir, it was empty. I promptly topped it up then checked underneath the car to see if any fluid was escaping down there, but no. Also nil for the garage floor. The following day I again checked the level, but yet again it was empty!
According to my mechanic chappie, he doesn't think the problem lies with the rear calipers, (as has been suggested on this forum - see under the Brake title) as the amount of fluid lost would show up with either a lot of fluid around the caliper or oil stains on the garage floor. Both these are dry. He suggests rather that the problem lies with the brake servo as the one in situ is most likely the original one and after some 38 yrs this is most likely the suspect!

Chris, if you can shed any more light on this issue, I would be obliged.

You do say, Chris that the prices quoted by Wins are a reasonable trade price, well be that as it may be. But I do think paying out £270 plus pounds for the item before any work is even started on repairing my motor, is a bit steep! Maybe it's me, living in the past when prices were reasonable. But whatever it is, Chris I would have to pay for someone else to do the work, as I am 67 this year and suffer greatly with my back. I have a plate & screws where a disc used to be, so bending or crawling under cars are now a no go. When I were younger I could do those things but not now!

I hope I have answered your query correctly.

Best Regards

Paul
 
Hallo Paul

Sorry to hear you're not quite as up to scrambling under your P6 as you used to be! I am in the same boat - but in my case it's an expanding waistline that limits access!

I'm afraid your mechanic hasn't met too many P6's. His logic for ruling out the rear calipers is impeccable on any other car - but not a P6. The location that leaks on the P6 caliper is buried well down inside the works. Above (or below, I can't visualise which way up the caliper sits for a moment!) is a space full of mechanism fr the automatic adjuster topped off with an air tight - and fluid tight - dust cover. So there is a lot of space in the caliper to fill up with fluid before anything appears externally.

Your mechanic may also have a bit of a surprise when he removes this dust cap. The mechanism within is there because the P6 caliper uses a mechanism to adjust both the handbrake and the footbrake, both of which operate on the same set of pads. In consequence the hydraulic piston that operates the foorbrake is both a very smal diameter and has a very short potential stroke. Should anybody have compensated for an ineffective handbrake by adjusting the handbrake cable, this wil have dis-abled the adjuster mechanism and wil lead to the hydraulic piston for the footbrake popping out of its cylinder, with consequential sudden fluid loss.

I'm almost certain this is what has happened with yours. The reason I say this is because the fluid is being lost overnight. Servo's, even when terminally defective, don't usually do that. You have to be operating the brakes for them to lose fluid. Plus I'd expect the lost fluid to have got into the inlet manifold by now and be causing clouds of white smoke from the exhaust, had it been filling up the servo reservoir. Of course there's always a first time.... but I doubt it.

So what to do?

If your mechanic has advised you this so far, I respectfully suggest he is extremely unlikely to cope with the innards of P6 rear calipers. If you know what you are doing they are reasonably easy, if not there will be springs and cogs everywhere! Even exchange calipers won't help him because the setting up of the pad adjustment and handbrake cable adjustment are likely to defeat him.

Luckily, anybody familiar with P6's will have done many hundreds of these! Even with the handbrake set up correctly, they are perhaps the most frequent failure point on the car. Accordingly they will be much cheaper than your local mechanic and will be able to guarantee success! The person most local to you is probably Nick Dunning, who operates from Godalming. I strongly suggest you give him a ring for a chat. His phone no is 07748 983948

I've put a link to Richard's (quattro's) photo story of overhauling calipers so that you can get a better idea of what I'm describing. Picture worth a thousand words and all that!

I hope that helps.

Chris

http://www.classicroverforum.com/viewtopic.php?f=14&t=8560&start=15
 
chrisyork said:
this wil have dis-abled the adjuster mechanism and wil lead to the hydraulic piston for the footbrake popping out of its cylinder, with consequential sudden fluid loss.
Click to expand...

If the caliper has all the parts in there, and in the right place, (whether working or not) this will never happen. Look in the parts book if you can't see why.
 
sorry Harvey, I thought I had understood, at least in part from your excellent knowledge, that if the handbrake cable is overtightened then the adjuster mechanism will no longer function?

Chris
 
chrisyork said:
sorry Harvey, I thought I had understood, at least in part from your excellent knowledge, that if the handbrake cable is overtightened then the adjuster mechanism will no longer function?

Chris
Click to expand...

It's not that at all. You say the hydraulic piston will pop out and you'll lose all the brakes. Regardless of how the cable is adjusted, and even if the entire adjuster mechanism, and even the pads themselves, are missing, that is impossible.
 
Ah, OK! Misread what you were driving at (or stopping before :D ). I still think the back brakes are the most likely culprit to drain down overnight though. Or perhaps the master cylinder into the bulkhead cavities? But definitely most unlikely to be the servo!

Chris
 
Many thanks for all your comments. I shall now read & digest.

Chris, Thank you for your most informative letter. One thing I forgot to mention, Chris is when reversing the car from my garage, there were plumes of white smoke coming from the exhaust. I just thought it was because the engine was cold! Have I made an error?

Paul
 
prospect8816 said:
there were plumes of white smoke coming from the exhaust.
Click to expand...

That could just be the condensation from the exhaust on a cold day, or it could be the brake fluid being drawn through the engine from the leak in the servo. If you smell the smoke you should be able to tell the difference. The best course of action is to check all possibilities. Remove the vac pipe from the servo and dip the chamber to see if it has fluid in it, check the pedal pushrod and drivers footwell carpet for signs of fluid there, and prize the rear caliper dustcovers back to see if you get a shower of fluid from inside there, then fix what you find.
 
RE: Chris's suggestion, I have today contacted Nick Dunning and had a quite detailed discussion with him. On the basis of that chat, he reckons the problem lies with the Master Cylinder and not with the servo! He goes onto say that the oil is most probably draining down into the bulkhead where it will lie until sudden movement would make it fly out.
Obviously he needs to see the car before he can be certain, which is why we have arranged for him to have the car collected on a trailer early next week to transport it back to his premises in Godalming.
If it is the Master Cylinder, then I have escaped paying out large sums of money for something I don't require, ie a new Servo!!

I must take this opportunity to thank everyone for their input, especially Chris York & harveyP6. Plus Ron c/o SydneyRoverP6B, as without all this valuable input the Forum would be a poorer place. Thank you.

I will keep you posted.

Paul
 
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