Power steering pump

[Fakejudge]

Hi. Picked up an M100 a few months ago and, amongst other things, needs a new power steering pump (or it refurbished if that's possible?). Not had much luck finding one. Very grateful for any ideas. Regards

[Fredjohn]

First of all welcome to LEC. We are a friendly bunch and the forum is packed with knowledge and info. It is also almost compulsory for new members to post pictures of the car, if you can work out how!

A location would also be helpful so recommendations can be made and any nearby fellow members can render assistance if required.

Now to the pump. Why do you think it needs replacing? Its effect is relatively minimal anyway and it often feels heavy in normal use. To minimise this a change of fluid can help and also the lower UJ becomes very stiff with age and should be replaced. Awkward job, but cheap, as a Land-rover part is identical.

Lower Steering Column U-Joint A100H0050F --> Land Rover Defender Lower Steering UJ NRC7704

Otherwise sjsportscars.co.uk do an exchange pump.....at a price, and I am sure other Lotus specialists offer the same.

Hope this helps.

[Tuga2112]

please dont take this the wrong way, but we have some frequent questions from new owners, and from the vast experience aquired, you will find the more experienced members (like Fredjohn) effectively advising you against the "obvious" solution to your problem,

As Fredjohn implied, we dont have a known record of PAS pumps failing. although many new owners assume theres something wrong in the pump or steering rack due ot the fact the steering is extremely heavy compared to modern cars, and pretty heavy when comparing to other period sports cars.

usually a change on fluid does have a slight improvement in the stiffness of the steering and the most common root cause for unusual steering stiffness is the U joint at the bottom of the steering rack (a right pain in the back [literally] to replace, but a rather affordable part.

I would strongly suggest to do the simple test of trying to turn the wheel on a less grippy surface (cement, or driveway brickworks instead of tarmac)and then starting the car and compare the amount of effort needed to turn the wheel.
also if you can find a owner located nearby, he will porbably be able to give your steering wheel a try and tell you straight away if its unusually stiff or not.

My first MOT in onwership of the elan had a failure on "PAS not working" where it was funcitonling as well as it does today. I had to refer to a few other people asking the same question back then to explain to the Tester the car was performing as it was intended.

[Simon_P]

Welcome!
As Fredjohn said.
It is also normal to hear a moaning noise and hissing. There is also a high load pressure switch in the pump underneath the pump make sure the wire hasn't fallen off.

[Fakejudge]

Many thanks all.
You may be right about the U joint - so as soon as I get the chance I'll check that. I did do some research and did note the threads about the steering being heavy. But it did seem that it was VERY heavy - as heavy as my FWD race car - and that doesnt have power steering. And it also seemed a bit inconsistent - i.e. at speed, harder one way than the other. That was probably the thing that worried me the most. I love the grip of it but it doesnt have much finesse at that weight of steering.
I'll check all the front suspension first and take it from there.
Regards

[Tuga2112]

Many thanks all.
You may be right about the U joint - so as soon as I get the chance I'll check that. I did do some research and did note the threads about the steering being heavy. But it did seem that it was VERY heavy - as heavy as my FWD race car - and that doesnt have power steering. And it also seemed a bit inconsistent - i.e. at speed, harder one way than the other. That was probably the thing that worried me the most. I love the grip of it but it doesnt have much finesse at that weight of steering.
I'll check all the front suspension first and take it from there.
Regards

when my U joint packed in, it was the same symptoms your describing. some wheel positions were harder to turn and then easier again after turning a little more

[Fakejudge]

Good info, thanks. I certainly hope its that - less expensive than a new pump!

[andrewp]

Power steering pump failure is not uncommon for a 35 year old car . . . it is usually traced to a major PS fluid leak and the elevated pump being run dry. The pump will be chirpy and it will exhibit a mm (or three) of pulley play.

The PS pump unit is serviceable and the rebuild kit is very reasonable (I use Rock Auto). It consists of one rubber grease seal, two or three small o-rings, and one large keyhole-shaped o-ring. NOTE: there can be variation in the shape of the key-hole o-ring (radius of corner curves).

With the exception of the keyhole-shaped o-ring, all the other seals can be inexpensively found from a bearing supply house. I have rebuilt 4 spare pumps for my collection. I most cases I have reused the keyhole-shaped o-ring.

In North America, several PS pumps from common cars are 99% identical to the Elan's.
1992 (perhaps other years) Asuna Sunfire . . . this is Canada-specific car
1989-1991 Isuzu Impulse XS or RS
1990-1992 Isuzu Stylus
1991 (perhaps other years) GEO Storm GSi (with the 1.8 DOHC engine)
1990-1992 (perhaps other years) GEO Storm with 1.6 litre SOHC

The steel pump mounting bracket is identical. The alloy pump body is identical. The steel internals are identical. What differs is the high-pressure fitting. If my memory serves me well, it is a tall threaded male fitting on the Elan (hose is a banjo connection sealed by two copper crush washers), while the hose for the other cars is a shorter in-line threaded flair fitting. These pump HP fittings can be removed and the Elan one swapped onto -say- a GEO Storm pump.

AP in Edmonton

[andrewp]

I failed to mention the most difficult part of this repair is pulling the old PS pulley off the pump shaft. Likely, you will need to buy a kit to do this. Following the pump rebuild, you will need another tool to press the pulley back onto the shaft. Some larger kits have both the puller and installer (press) pieces in one case. Expect it to be $30 to $50 (Canadian) for a generic kit. Or spend $250 for Snap-On.

The pump shaft is shouldered . . . so the pulley height need not be measured. Just press it onto the shaft until it bottoms out on the pump shaft shoulder.

AP