PAS Pump Outlet Fitting - Leak arrggh


New Member
Original OE drawing attached for the power steering pump.
The .7” refers to the length of the roller vanes / cam width.
The middle figures of the part number 5541/9522/1, gives the normal performance of the pump, 95 = 950 psi relief pressure and 22 = 2.2 gpm flow.
Unfortunately the drawing for the orifice tube is fairly useless, still searching for the two HEMS documents that are stated.



Well-Known Member
Hi, Interesting, but a further point of interest is what part of a part/serial number denotes direction of rotation and what detail differences are there?

Sorry to the OP for going too far off topic.

The first 4 numbers give the pump model variation, I’m only aware of the top level drawing defining the rotation. The last digits define the options provided, such as elbows, pulley, mounting flanges etc.
Finally found the drawing for the orifice tube, see attachment
Can you advise if this pump unique to our cars ?
The pump number 5541/9522/1 I believe is unique to the P6B. In the drawing files there is only the one assembly for the 5541 model style. The unique features could be the bearing cover only being retained by one screw, I assume because the screw is only used to secure the cover during shipping, it is replaced by the Rover mounting bracket and bolts when installed, and the threaded holes in the rear of the pump body for the fitting the rear Rover mounting bracket. The /1 I’m sure would be for the aluminium elbow and the banjo bolt for the supply port.
It is possible that there are other 5541/****/1 pumps with different pressure and flow setting as these are not defined on the drawing as they would now days. These must of been controlled by notes on the works order during production.
These pumps I believe were designed in sizes 0.5”, 0.7”, 0.9” and 1.1”, this dimension refers to the width of the cam which therefore gives the basic capacity of the pump. The capacity is matched to the size of the steering box or rack (or gear for our USA friends) that is fitted to the vehicle.
There could be many other 0.7” size pumps that would be close to the P6 version or ones that could be easily modified. Flows and pressure relief setting can be increased but cannot reduced without replacing parts.

if anyone needs further information on these pumps I’m willing to help as much as I can with the records that I have access to. Last week I did find the factory repair instructions for the these series 30 pump, only in hard copy form but will scan it so that it is available for emailin.