Heater pump brushes size?
 

Howdy All,
I'm noticing the heater isn't getting too warm ('02 XJ8), and after doing some searches here, see that the heater pump brushes wearing out is a strong candidate for the cause. I would like to have new ones handy before I start working on and disable the car...Does anyone know the heater pump brush dimensions and/or a source for them here in the US (e-bay seller maybe?) ?

Also, are there any tips,tricks, or cautions when backflushing the heater core (matrix) and associated valves and hoses that I should take care to not screw up?

Thanks a Bunch for any guidance!

Some pics for you Dave -

Attachment 153321

The pic shows the system looking through the firewall. The plumbing works as follows -

Attachment 153322

If you do rebuild the pump you won't find the correct brushes. They are 12mm x 5mm x 5mm with braided tails. You might find near equivalents but you'll have to file them down.

However, the tails aren't needed. The current draw is so small that you can cut the braid off of the existing brushes and solder it to the brushholder. Power will get to the brush via the casing and spring.



The armature won't come out completely because of the bearing. If you take it off measure EXACTLY where it is on the shaft as it doesn't fit against a shoulder. Get it wrong and the pump will be seized on re-assembly. To fit the brushes prise open the 'flaps' on the end of the brushholder and slide the new brush in followed by the spring. Then fold the flaps back. If you test the motor prior to refitting make sure you get the polarity right. The little diode between the brushes melts to a dead short if you get it wrong!

Sorry - I didn't say that you can get the 12mm x 5mm x 5mm brushes off of you know where, but without the braids.

Thanks for the brush size,tips, and your time JimForrest! The pic and schematic are even more accurate than the one I was looking at... :icon_clapclap:

brushes for heater pump
 

I know this is an old thread, but I recently had to replace the brushes on my pump and I'm sure others are still facing the problem. I found Standard Ignition FX65 at my local auto parts store in stock. The width on these is about right, but I had to grind down the length and height to get them to fit, and clip the ring connectors off the ends of the wires. Worked great.

I should add that my car is an XK8, but it's the same pump as on the XJ8.

I’ve also found the brushes available on eBay albeit not quite the same size as original ones. I’ve got a few of these pumps kicking around in various stages of brush degradation, I should just bulk buy a load of new brushes and make myself a little stash of ready to go ones.