PAS hose routing - how and why?

Andrewg10rover

Andrewg10rover

Member
Hopefully a quick and easy one: Can anyone describe the route the two PAS hoses should take from the steering box to the pump? (P6b, RHD).

Am I right that the low pressure hose should go in front of the radiator in some way, for cooling purposes? - and if so, should there be some means of holding it there, like some clips, or some such? Thank you in advance, Andrew
 
Hi, The circuit starting at the reservoir is, down the left hand inner wing to the pump, High pressure line across the front of the engine and up the right hand inner wing to the steering box and then the lower pressure return line across the back of the engine bay to the reservoir. So in short a trip round the 'bay. Various metal 'P' clips support to inner wing, water pump bolts, inner wing again and then to the heater box.

Colin
 
colnerov said:
Hi, The circuit starting at the reservoir is, down the left hand inner wing to the pump, High pressure line across the front of the engine and up the right hand inner wing to the steering box and then the lower pressure return line across the back of the engine bay to the reservoir. So in short a trip round the 'bay. Various metal 'P' clips support to inner wing, water pump bolts, inner wing again and then to the heater box.

Colin
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The supply from the reservoir to the pump goes across the bulkhead in front of the heater, down the driver's side inner wing, then it's clipped to the bolt in crossmember under the rad, into the pump. The high pressure goes from the pump over the front of the engine clipped to a bracket on the two long water pump bolts, up the drivers side inner wing to the box. the retirn from the box to the reservoir runs arcross the bulkhead .

I have no idea why the pump supply doesn't go down the nsf inner wing.
 
Thank you Harvey. It does seem a bonkers route for the low pressure feed to the pump. I'm tempted to take the more obvious route, unless anyone tells me that's not advisable...
 
I’ve just had another look. The angle of exit from the reservoir doesn’t lend itself to the shorter route. Maybe Rover just used old P5 reservoirs and couldn’t be bothered changing things. I’ll stick with what I have for now. I have enough other problems to resolve...
 
I think Rover ran those two thick hoses across the bulkhead because thay can make changing the bottom heater hose a bit of a PITA!
 
harveyp6 said:
The supply from the reservoir to the pump goes across the bulkhead in front of the heater, down the driver's side inner wing, then it's clipped to the bolt in crossmember under the rad, into the pump. The high pressure goes from the pump over the front of the engine clipped to a bracket on the two long water pump bolts, up the drivers side inner wing to the box. the retirn from the box to the reservoir runs arcross the bulkhead .

I have no idea why the pump supply doesn't go down the nsf inner wing.
Click to expand...

Hi, That's interesting, I've never paid much attention to the few previous ones, which I just daily'd, but the last two I've had, my present one and a spare PAS kit, have been as I described. Methinks it's someone else's doing then.

Colin
 
Hi Colin. How does the low pressure hose arrangement cope with exiting the reservoir at 90 degrees to its eventual direction of travel down the near side wing? Is there a u bend or something like that? - or just a big loop?
 
The long hoses in the circuit might be to help cooling of the oil by increasing the surface area that the oil passes through.. However rubber hoses are not the best material to conducting heat away!
 
Seems some cooling is important in PAS oil. I added PAS to the MX5 (for the missus), and one of its hoses had a loop of alloy tubing in it . This tube had to be placed in front of the radiator from the near side, and it was a real PITA to get it in there. The Porsche 928 however does not have any cooling in its PAS hoses....IIRC.
 
jp928 said:
Seems some cooling is important in PAS oil. I added PAS to the MX5 (for the missus), and one of its hoses had a loop of alloy tubing in it . This tube had to be placed in front of the radiator from the near side, and it was a real PITA to get it in there.
Click to expand...

My Rover 620 had a PAS cooler, and when it sprang a leak I bypassed it and haven't had any problems since, I also bought a Ford F350 and was told when I went to look at it that "it hasn't got PAS" which was true at that time because it wasn't working, but when I got that back to the yard I found that the PAS cooler on that was leaking, so that one got bypassed as well, also without problems.
 
In our mild British weather a PAS cooler is probably not required, however vehicle manufacturers have to design and test for all climates. Stand modern testing requirements are often -40 to 135 degrees C are common.
Higher operating pressures on modern vehicles tend to raise the working temperature.
 
The length of the hose and the circuitous route serve as far as I can see two functions. Increase the capacity of the system, and assist with heat dissipation. The route of the hose allow permits placement across the valance where it is exposed to a stream of air.

Ron.
 
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