THE INTERNATIONAL JAGUAR 'S'-TYPE REGISTER FORUM

I no that I have wittered on about the power steering on my car but after reading the thread on steering wheels I feel that I need to ask the question.
When I bought my car it had been converted to neg earth with an alternator so the original power steering pump had been modified to run on a pully driven system rather than from the back off the dynamo. This pump had a bad leak that could not be cured so I searched for a replacement, I bought a pump that was off an early range rover (model 5503) which was the same design apart from being pully driven but physically larger. So after all that has gone before I suspect that the pump that is on my car is possibly putting out a lot more pressure than was original. I don't know what the pressure from the Rover pump is , so what do you think !!!.
If it is high I might in the future be able to get the pressure down so this would help my steering issues


Regards

John

1B1257BW

Hi John. I'm not sure what the output of the Range Rover pump would be - probably higher than the original S-type pump.

Do you still have the original PAS Reservoir? Or is the reservoir now integral with the Range Rover pump? A photo would help!

To me, if you still have the original PAS reservoir, the neatest and most original solution would be to replace the alternator with a LMP072 Dynator (alternator within a dynamo case) (http://www.wosperformance.co.uk/products/dynators/) and source an original Hoborn Eaton PAS Pump from ebay to go on the back. There are a few on there at the moment. If you were to have the pump reconditioned, you could ask ICS or whoever does it to reduce the pressure to, say, 800psi to give you more feel.

I have not long replaced the alternator so I would be reluctant to replace it , the power steering is still using the original remote reservoir and the pump that is now fitted a Holborn Eaton pump but just physically larger, also after spending £200 for the pump to be rebuilt again reluctant to change. It was just the possibility of either adjusting the pressure valve or putting an in line remote valve , but this would be for a time in the future.
I think the first thing is to, A find out what the 5503 pump runs at compared to the original, B check what pressure I am getting ,and C see if the pressure can be adjusted. I also like the idea of a smaller steering wheel this would help me .


Regards John


1B1257BW

Fair enough.

I suggest you contact ICS and see what they have to say about your questions: http://www.ics-steeringspecialist.co.uk/.

Thank you for the link, I will have a word, also If I had known about the pressures I could have asked the company who rebuilt the pump to try and set the pressure for me to 800-850psi


Regards John
1B1257BW

I removed the valve bypass spring from the original pump and compared it to the spring on a pump that is the same that is now fitted to the car and from the pictures you can that the one on the left which is the original pump spring is slightly shorter than the one on the right as fitted now. So the plan is in the Autumn I will get the garage ( while the car is serviced) to swap the springs over so the shorter one is fitted to see if it stiffens up the steering as hopefully the shorter spring will allow the bypass valve to open earlier

Thanks, John. Those pix certainly do help us see what you're dealing with.

Of course, with any spring, it's not just the length but also the poundage, so probably worth comparing the two before incurring too much cost/effort.

Keep us informed. A number of us are interested.

http://www.jagstyperegister.com/forum_n ... 3890#p3890

I would love to know what normal operating pressure is because I would presume, maybe incorrectly, that you only hit max pressure at full lock?

according to the WSM the early units pumped at 800-850 but the later versions were increased to 1000l psi and yes I guess they are the max psi on full lock. I think that the spring pressure is aroundd 8lb from memory


Regards John
1B1257BW

For interest. Move to HE roller type pump. Pressure is checked at full lock.