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Water pump differences.
Posted: Wed Nov 17, 2010 12:05 pm
by DaveEFI
The pump on my SD1 EFI is leaking, and new ones cost an arm and a leg.
RR EFI ones from the same period are cheap. So what's the difference?
I have obtained a new one - but the supplier says they are no longer made. So it might be prudent to know which parts have to be changed to use an available one in the future.
Also, at one time they were a service exchange unit. All of mine have failed due to a leak, rather than bearings. Might it be possible to fit new seals?
I have at least three leaky ones lying around.

Posted: Wed Nov 17, 2010 1:24 pm
by SuperV8
RR water pumps pre serp are larger/ heigher than the SD1 so you'd also need the appropriate front timing cover to fit.
Tom.
Posted: Wed Nov 17, 2010 1:28 pm
by ChrisJC
SuperV8 wrote:RR water pumps pre serp are larger/ heigher than the SD1 so you'd also need the appropriate front timing cover to fit.
Tom.
Indeed. 'Completely different' springs to mind....
Chris.
Posted: Wed Nov 17, 2010 1:59 pm
by ian.stewart
I think real steel sell new SDi style pumps quite reasonably priced,
Posted: Wed Nov 17, 2010 2:27 pm
by DaveEFI
ian.stewart wrote:I think real steel sell new SDi style pumps quite reasonably priced,
There are several different ones used on the SD1. I've got an EFI which seems to be the difficult one.
Posted: Wed Nov 17, 2010 2:29 pm
by DaveEFI
SuperV8 wrote:RR water pumps pre serp are larger/ heigher than the SD1 so you'd also need the appropriate front timing cover to fit.
Tom.
I suspected something like that. Wonder if the different front cover could be used on an SD1? Just looking towards the future if they can't be got at any price.
Posted: Wed Nov 17, 2010 3:55 pm
by katanaman
yes you can fit the RR front cover if it all fits bellow the bonnet line and behind the radiator. As said it all sits a lot higher which is why the saloons are the way they are. You would also have to fit all the pulleys and brackets from the RR as well and maybe the alternator.
I thought there were only 2 saloon pumps the P5-6 and SD1, I didnt know the EFI had a different pump. Maybe the none EFI pump can be fitted with little hassle?
Posted: Wed Nov 17, 2010 5:08 pm
by Ian Anderson
And I can throw in another
I have a 3.9 Hotwire 1990 unot and it runs a P6 Waterpump
Try E bay
http://shop.ebay.co.uk/?_from=R40&_trks ... Categories
Check if they look like your existing one
Ian
Posted: Wed Nov 17, 2010 5:21 pm
by DaveEFI
katanaman wrote:yes you can fit the RR front cover if it all fits bellow the bonnet line and behind the radiator. As said it all sits a lot higher which is why the saloons are the way they are. You would also have to fit all the pulleys and brackets from the RR as well and maybe the alternator.
I thought there were only 2 saloon pumps the P5-6 and SD1, I didnt know the EFI had a different pump. Maybe the none EFI pump can be fitted with little hassle?
The EFI has a temperature sensitive viscous coupling - the type with the left hand thread. Most later V8s used the same idea. I'm not sure if the front cover of the engine is the same, though, on all SD1s.
Posted: Wed Nov 17, 2010 6:23 pm
by katanaman
ah ok well sounds like a normal sd1 pump and an electric fan might do the job assuming the cover is the same. A quick pic would show whether it is or not.
Posted: Wed Nov 17, 2010 6:25 pm
by ged
P5,P6 & SD1 all used the same basic water pump casting shape. The differences being the pulleys, fans & viscous couplings but they are all adaptable to each other.
Posted: Wed Nov 17, 2010 8:50 pm
by ChrisJC
You might be able to press the boss off the shaft. I certainly moved one along a bit to convert a Range Rover pump to an LDV pump.
Chris.
Posted: Thu Nov 18, 2010 12:19 am
by DaveEFI
ChrisJC wrote:You might be able to press the boss off the shaft. I certainly moved one along a bit to convert a Range Rover pump to an LDV pump.
Chris.
That's interesting - wonder if it's possible to fit new seals? If you can get them. I have several which are sound, but leaking.
Posted: Thu Nov 18, 2010 12:47 pm
by SuperV8
Regarding the height I used the RR water pump on my Dax Rush (even though most people were struggling to source SD1 front covers/pumps) with no problems and I had to cut a hole for the plenum to poke through so i'd have thought the SD1 would have a higher bonnet line as the plenum fits under the bonnet!
Tom.
Posted: Thu Nov 18, 2010 1:07 pm
by ChrisJC
SuperV8 wrote:Regarding the height I used the RR water pump on my Dax Rush (even though most people were struggling to source SD1 front covers/pumps) with no problems and I had to cut a hole for the plenum to poke through so i'd have thought the SD1 would have a higher bonnet line as the plenum fits under the bonnet!
Tom.
I suspect it's more to do with where the fan sits than bonnet clearance. The rad / fan in an SD1 is much lower than in a Range Rover.
Interestingly however, the GEMS timing cover puts the fan much lower than in a Range Rover classic......
Chris.