CX 2500 auto LHM pump rebuild?

UFO · Post by **UFO** » 04 Jul 2008, 12:14

My wife's CX2500 has a gradually failing LHM pump. I have sourced a 2nd hand replacement (automatics have a different front plate from other models) and I want to rebuild the replacement before I fit it.

I have recently had the pump for my D Special rebuilt and the change in the car was amazing. You don't realise how tired and slow they get until you replace them.

So, can someone advise if they know of a method of rebuilding the pumps for CXs?

Thanks.

andmcit · Post by **andmcit** » 04 Jul 2008, 12:34

Some of the earlier generation s1's had a substantial pump as per the D
models but then changed over to a smaller sealed pump so I don't believe
you can get it reconditioned - try offering a D one up though!

Andrew

<edit> just realised the title says auto! Don't think there was any different
inline with the crank pump than the one's fitted throughout Cx's production.
I know a mounting was changed for AC too mind...

UFO · Post by **UFO** » 04 Jul 2008, 12:52

As crazy as that sounds it might just work. I have a spare D pump laying around so I will have a look at it over the weekend. I think the pulley may even be the same diameter. A seven piston pump might add a bit of grunt to the system too.

Pleiades · Post by **Pleiades** » 04 Jul 2008, 14:07

The five cylinder pump as fitted to the later CX can be rebuilt, we do this all the time, but there are many pitfalls for DIY as the pump is a press together job, whereas the earlier CX pump was the same as the DS, a 7 cylinder pump, this is a much more simple type of pump as it is held together with nuts and bolts!

There are 3 different types of 5 and 7 cylinder pumps, generaly it is the tensioning bracket , this can be moved on the 7 but not on the 5 as it is cast into the housing, the other type is the shaft driven pump, this was fitted mainly to automatics with aircon fitted.

Putting a 7 cylinder pump on the car will not give it any extra grunt as the 7 cylinder pump has a lower output than the 5 cylinder (slightly less cc per minute at the same speed)

5 x big pistons with a longer stroke will supply more fluid that 7 x small pistons with a short stroke.

But of course whatever speed or capacity of the pump, the hydraulic system is regulated to a max of 175- via the regulator, so whatever pump you fit, you should not notice any difference in the hydraulics, assuming that the main and brake accumulators are working fine.

Martin

UFO · Post by **UFO** » 04 Jul 2008, 14:31

Thanks Martin - of course what you say re the pump volumes is correct. I was not implying that there would be difference in the pumps other than the time to rise etc....

Anyway, I have just sent and email to Peter here in Aus re getting a pump rebuilt. I await his reply. Good to know it can be done though.

For others, this is the belt driven pump, not shaft driven, and this pic shows the difference in the mounting bracket - our 2500 Auto with AC (working AC by the way) has the bracket type as per the pump on the left. Of course the spare 2nd hand pump I have at present is the type on the right. Doublechevron had the two pumps in this photo and the one on the left is on its way to me.

http://www.aussiefrogs.com/forum/attach ... 1215048259

I have also seen a CX2400 Prestige Auto here that has the same pump.

Pleiades · Post by **Pleiades** » 04 Jul 2008, 16:50

Both of the pumps in the photo are the same except that the adjustment bracket is at a different position.

In otherwords, if you can make up a bracket to adjust the "wrong pump" it will work.

Martin.