Had a set of Pace RC36 tucked away for a while. Have finally got round to using them in anger and there is a decided thump as the fork goes to maximum extension. is this normal?

Nope.

Does the damper work? could be that can still be serviced by forkengish

Have a good read through the Manual, located on the Pace web site.
I was looking at the RC41 Fighter one, as i was going to buy some.

and i remember reading something about that being perfectly normal for Pace forks, in certain circumstances.

But have a look on the Pace web site, and a good read of the manual.

Thanks guys. Located in Aus so I think semding to Fork English might be a touch expensive

Will go and have a look on the Pace website.

I had that problem on my rc40s.. Something to do with the damper and the lock out.. Would clunk at full extension when going over a drop..
Seem to recall the solution was constantly engaging the lock out and cycling the forks downwards..
The lock out/down wasn’t very effective at first but after 6 or 7 goes it started working properly and the clunk would disappear..
Just realised its the rc36 you have so might be different.. Sorry!