15 replies to this topic

[cheesebadger]

Has anybody ever done this? I managed to get hold of a cheap PCV valve, and wish to take it apart to check the condition of the diaphragm etc. There isnt anything at all to grab hold of to pull the lid off, i thought about pushing from underneath but that would definately ruin the diaphragm.

Any help appreciated,

Rich

[cheesebadger]

Anyone, any help at all!

[Guess-Works.com]

That's because it's a non service item...

[bmcecosse]

And was never a great success. They soon dispensed with it.

[cheesebadger]

That's because it's a non service item...

But you can by replacement diaphragms from minispares, and service kits from somerford. Surely this makes it a serviceable item...

Thanks for replies,
Rich

[Guess-Works.com]

Put it this way, was never in the rover parts catalogue as a service item.... only available as a replacement unit..

I make the assumption that you mean the one on the bulkhead ( the older one on the rear subframe is servicable but as bmc* says, this was eventually done away with

Edited by Guess-Works.com, 26 January 2010 - 10:13 AM.

[GraemeC]

Are you all talking about the same thing here?!!

I read PCV valve as being the one on the inlet manifold on early cars for crankcase ventilation. Where does bulkhead and rear subframe mounting come into it?

If my understanding is correct then you will probably have to lever the top out with a small screwdriver down the side. A strong magnet may help too as I guess the cover is steel whereas the body is cast alloy.

[cheesebadger]

Im confused by the bulkhead aswell? Do you mean the brake compensator valve?

Yes i meant PCV valve as positive crankcase ventilation on the inlet manifold. I tried levering the top out, but didnt want to try too hard and break something. A magnetic is a genius idea, i shall try that aswell.

Cheers,
Rich

[Guess-Works.com]

my apologies.... was obviously not awake....

[cheesebadger]

my apologies.... was obviously not awake....

Not a problem, it happens. Thanks for the reply anyway

[Ethel]

It should just be held together by the spring clip that goes over the top. If it won't pull apart it's probably a perished diapragm holding it together. How about a blast from an airline with the inlet blocked off?

[GraemeC]

For the price of the diaphragm I would be sacrificing it and then be happy in the knowledge I had overhauled the valve with a new one.

[cheesebadger]

It should just be held together by the spring clip that goes over the top. If it won't pull apart it's probably a perished diapragm holding it together. How about a blast from an airline with the inlet blocked off?

I have removed that, i think it is just a bit corroded. I just didnt want to start over stressing it, having not taken one apart before.

For the price of the diaphragm I would be sacrificing it and then be happy in the knowledge I had overhauled the valve with a new one.

That was the plan, get inside and have a look what the condition is like, its only £5 for a new diaphragm! Am i correct in thinking that when i fit this valve, if it fails then the crankcase pressure will become excessive and cause more oil leaks?

[Ethel]

No, the inlet (without forced induction) will always be at or below atmospheric pressure. The valve stops excessive manifold vacuum being transmitted to the crankcase on overrun (engine braking). If it failed you'd most likely get an air leak in to the manifold causing it to idle like a bag of spanners.

[cheesebadger]

Oh ok, that makes sense. I think thats what i meant, just if it failed and stuck open then excessive manifold vacuum would be transmitted to the crankcase during overrun. Anyway, thanks for the help. I shall have a proper go at taking it apart in a few days. Uni exam tomorrow, Vehicle Dynamics, fun fun!

Thanks for all replies,
Rich