The Lotus Grand Tourers

I'd go with pump issue too. After similar intermittent heaviness, renewing mine with a NOS from SJS restored it completely. And btw, my rack was new when the intermittent heaviness was present.

When mine gets intermittent it's always just an inadequately tight drive belt. For some reason, even with a new belt, I seem to be usually near the end of the adjustment range, and it does lose tension and the power assistance stops working after a while.

After 12 years of hating the really awkward access to tighten it up from under the car, I discovered yesterday how much easier it is to do it from above, if the bonnet is removed - which isn't exactly hard to do!

My steering has been getting heavier, 86 Excel SE. Try bleeding the system, which is done very easily - with engine running, turn the steering one way until it's on full lock and hold it there for a few seconds. Then turn the wheel fully the other way and repeat. That's what the workshop manual suggests as a way of purging air from the system, and it improved mine for a while.

Check your PAS fluid is red. If it looks brown try sucking it out with a syringe and get some fresh stuff in there - that may also help.

I think I'll need to replace the pump and rack on mine with refurbed items one day, but the lock to lock bleed process definitely helped.

Cheers

John

One other thing, make sure your PS belt isn't slipping. It's a horrible job to adjust on the 86 model year cars, but worth checking.

Cheers

John

This winters project started with a change of steering pump. Made no difference, was actually worse, which I now know was down the the pressure relief valve in the new pump sticking very soon after fitting.
Drained down the fresh fluid and could immediately identify there was metal contamination in the fluid ( earlier drained fluid was so dark, it hid any contamination). I believe this swarf jammed the relief valve open.
Rack removed and both pump and rack taken to be refurbished / checked.
Collecting tomorrow but been told the rack was probably the main problem causing my intermittent power steering. They've also flow tested the new pump and fitted the relief valve from the old pump. Now a good pump again.
I'll report actual findings once I've collected.
Just got to make sure I flush any last contaminated fluid out of the pipes and reservoir before refitting.
Tony

Drawing a conclusion to this thread, power steering wasn't working all the time and it is most probable that the cause of my problem was the rack.
To recap the problem, at slow manoeuvring speeds often the steering was just so heavy it was hard work to turn. Adding a little revs bought the fluid flow up a little and sometimes it would get easier, but not always. Once underway, steering felt fine, but that's probably not too surprising.

Unfortunately the rack was past the point of economical repair, but the specialist in B'ham who did the rebuild of the rack (Kiley Clinton) had an old "outer" which they used to make one good rack out of the two halves.
Picture below shows the inside of the rotary valve block. The 4 neat concentric rings towards the bottom shouldn't be there. They have machined themselves over the years with the Teflon seals acting as the cutters


This part of the rack is aluminium. In hind sight, one of the tell tale signs that not all was right would have been the condition of the Fluid. It was very dark, which KC told me was typical of fluid contaminated with powdered Aluminimum.

I'd recommend anyone with a reasonably high mileage car to drain the steering fluid check it's condition for colour and swarf and replace with fresh. You might just save a rack by removing the mildly abrasive fluid.

Tony