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Hydraulic tappets

Posted: 02 Apr 2013, 19:30
by project25
Hi, Anybody had this one. Got to the stage of booking MOT, ie got the engine running as good as. Yesterday had to remove old gas heater from under the van, so jacked it up on one side, worked for maybe 1 or 2 hours then removed from ramps and engine was clattering. Left it and returned today, when started sounded like hydraulic tappets had drained. When I looked at tappets 1 exhaust tappet had about 1/4" free play. This was on the "low" side when it was up on supports.Why can 1 tappet suddenly get loads of free play?

Re: Hydraulic tappets

Posted: 02 Apr 2013, 20:10
by California Dreamin
It's all dependant upon where the engine stops and which of the tappet ellements is loaded (if the valve is being opened)...the ellement is then under valve spring pressure for several hours and in a worn condition slowly bleed off.

Martin

Re: Hydraulic tappets

Posted: 02 Apr 2013, 20:32
by project25
Hi, Thanks for reply. Does this mean it will pump itself back up if I was to go for a run?

Re: Hydraulic tappets

Posted: 02 Apr 2013, 20:33
by kevtherev
it needs up to a twenty minute drive now to fill it up

Re: Hydraulic tappets

Posted: 02 Apr 2013, 20:37
by Ralf85
kevtherev wrote:it needs up to a twenty minute drive now to fill it up

And drive along at about 50mph and it should settle down again.

Re: Hydraulic tappets

Posted: 02 Apr 2013, 20:57
by project25
Cheers for that, shall give it a run tomorrow

Re: Hydraulic tappets

Posted: 02 Apr 2013, 22:04
by California Dreamin
Indeed...these engines are known for this happening.
A good fast drive.....keep the engine unstressed until warm, the oil needs to be hot to purge out the air.

Martin