Hydraulic Tappets

[Fully Loaded Cali']

Ok, I know there's loads on adjusting these, but..

After replacing a leaking pushrod tube I reset the tappets. Upon winding off the adjuster thought that the 'pre-load' was now where near 1.5 turns.

So, wound adjuster to contact (valves shut) and then an additional 1.5 turns. Only did this to cylinders 3 & 4 as that's the rocker gear I disturbed.

Engine wouldn't fire. No compression, as if valves open.

The only way to get running again was to wind adjuster to contact valve stem, then only a 1/4 turn (same as they were before I started roughly).

I've had a good look at the rockers and the contact faces show very little wear, in fact the whole lot looks very good.

Will 1/4 turn be ok? Had the van 3 1/2 years done loads of miles with no issues...

Am I doing something wrong or is there some underlying problem here?

Note: Push rods are fully home in the tappet seats, piston fwd with valves shut (rockers back pos'n)

[kevtherev]

are they hydraulic..How do you know?

[Fully Loaded Cali']

are they hydraulic..How do you know?

it's a 1984 DG - could they not be?

I'm assuming here all T25's were Hydraulic, but assuming is dangerous.

Good to see you again

[kevtherev]

are they hydraulic..How do you know?

it's a 1984 DG - could they not be?

I'm assuming here all T25's were Hydraulic, but assuming is dangerous.

Good to see you again

You too mate.
Is the non valve adjust sticker still present on the duct?

[itchyfeet]

there was one reconditioner in the past who used solid lifers as they are lower cost.

[kevtherev]

Best way to check are the pushrods.
See the Ratwell guide for the differences

[Fully Loaded Cali']

No stickers as I can see.

Last year a couple of times I suffered from what I thought was 'tappet drain down'. Engine sounded like a bag of spanners, clanking clearly coming from the rocker gear after I had parked up with a hot engine and didn't fire it up for a couple of weeks. It quietened down after a ten minute run.

Sounds ok now and runs fine, although only tried driving around a farm yard.

[kevtherev]

OK well that's encouraging.
Ideally..
You have to work through the valves from cyl one to four.
Ideally with pumped up tappets left to cool untill just warm.

Cant understand why you had to faff with the settings anyway, if you just removed the train.

Are the rods located ok?
there's no hard and fast rule regarding turns in..it's just that the majority do 1.5

[Fully Loaded Cali']

OK well that's encouraging.
Ideally..
You have to work through the valves from cyl one to four.
Ideally with pumped up tappets left to cool untill just warm.

Cant understand why you had to faff with the settings anyway, if you just removed the train.

Are the rods located ok?
there's no hard and fast rule regarding turns in..it's just that the majority do 1.5

I'm always faffing

I'm gonna check the other side now, see how they are set...

[kevtherev]

OK well that's encouraging.
Ideally..
You have to work through the valves from cyl one to four.
Ideally with pumped up tappets left to cool untill just warm.

Cant understand why you had to faff with the settings anyway, if you just removed the train.

Are the rods located ok?
there's no hard and fast rule regarding turns in..it's just that the majority do 1.5

I'm always faffing

I'm gonna check the other side now, see how they are set...

OK, BTW I doubt very much you kept the valve open, the lifter piston only has 4mm of stroke.
Does it clatter now that it's back to a 1/4?

[Fully Loaded Cali']

Right, they are defo hydraulic, found my sticker (was on top of my carb cover ).

The engine does seem to clatter, as if got a small hole in the exhaust. I had a 1.9dg crew cab once and that was silent, amazingly silent!

If I wind more than 1/4 turn, when I turn the crank shaft pulley there seems to be no compression on that cylinder, and the engine won't start or will start VERY lumpy won't rev then dies.

I didn't check the other side. Wednesday is the next time I can get to it, I will run up to temp, let it cool then do the whole process again (be the 5th time!!!) but this time without a hangover (Saturday night turned into a heavy night!!)

I'm now wondering if - at the point where I think I've contacted the valve, in fact I've past that point and already started the 1.5 turns.

Just to clarify, the push rods are defo located into the tappets.

If I can only adjust 1/4 of a turn, I'm wondering whats wrong??

[kevtherev]

Do it properly and put them to zero lash.. no turns in
Don't adjust one, adjust four, do 3, leave 2 on the firing strokes adjust at TDC
run the engine.

[Fully Loaded Cali']

Do it properly and put them to zero lash.. no turns in
Don't adjust one, adjust four, do 3, leave 2 on the firing strokes adjust at TDC
run the engine.

I'll try that. Cheers.

[kevtherev]

it will clatter on zero lash.
but it should offer the lifter maximum stroke to fill up.
once it's warm preload it a 1/4 turn on any stroke
initial setting is crucial here.

I don't think you can hit valves on a DG.

[Fully Loaded Cali']

Sorted. Ran for 5 mins, re-adjusted to 1.25 turns, engine fires and runs quiet.

Can't think what was wrong before.

Maybe 1/2 a bottle of Honey Jack Daniels the night before

Thanks Kev.