I've got the same heater pump problem. Thought I would share a couple of my diagnostic approaches . All of them can be done with the engine off, cool, in a quiet environment.

1) You can unplug the Motor connector ( Black) at the firewall, and do a continuity check at the plug. It should show continuity if the brushes are intact. Mine Didn't.
2) You can apply voltage and ground directly to the connector. Make sure +Voltage is applied to the Yellow wire on the connector, ground to the black connector. You should be able to hear the motor running. Mine Didn't.
3) You can also apply 12V directly to the 10 amp fuse for the motor. A simple wire jumper from the "hot" post beside the fusebox to one of the two small metal posts at the top of the fuse will apply power. It doesn't matter what side of the fuse you apply the power to , if the fuse is good. Fuse is marked #15 in the engine bay Fuse panel, Left side of engine bay.
4) You can pull the Heater Pump relay, and insert a jumper between the 30 and 87 holes. This supplies power to the 10 amp fuse, and thus to the motor. Again, should hear the motor running. Relay is at the top of the "T" of relays in the fuse panel box, and is the relay closest to the windshield.

I could not find the brushes referenced on the site, so I did some research and found some that were cross referenced. Bought them on Ebay for $6. Should be here this weekend, and then the fun will begin. I will need to sand down the brushes to make them fit. ON Ebay, "New Alternator Brush Kit For K1 *Bosch* 9124080140 - 38-9100" , https://www.ebay.com/itm/113824830739

 

Remember you can sand the brushes down to fit as mentioned in my write up.

 

All great suggestions. I started with the fuse and it's good. Too dang cold and wet to play with the rest.

 

Hi Gus! Thanks a ton for all this info. I'd previously done all the trouble shooting you'd mentioned. Yup - my motor's dead. I've got a used one in stock, but if only the brushes are shot in my original (and the bearings & vanes are still good of course), putting in those new brushes would be preferable. Does the eBay "Kit" come with one or two brushes? The ad doesn't say. How much did you need to sand off, and are the brushes stout enough to survive a dremel sanding until almost the right length? That would definitely shorten sanding time.

I'm just cringing at this job. I truly hate going back in there. (sigh, .... but there's work to be done) :-)

Thanks again

 

I know nothing about the E-Bay kit that you are talking about but if it is a rebuild kit for the pump motor for that pump it will probably fit. Brushes come in various sizes and can be sized to fit your application simply by placing a sheet of sandpaper on a flat surface and moving the brush back and forth on it to size remember they are made of carbon. Just remember you can always remove more but you cannot put it back on. If it were me I would measure the old brushes and see if you can find that size brushes on Google.

 

Oops. It was Darbysan that found the kit and posted the link. I hit "quote" in the wrong post. Hope you're doing great anyway! :-)

 

Much Thanks to all those that came before me, and made this a doable task. Couldn't have done it without the inputs from this forum! Kudos!!!

Final Wrap-up on my repair. Got the pump out, took it apart. The brushes were just about worn out. One side had worn enough that the wire attached to it had worn through, causing the Open circuit. Everything was repaired per this thread, and went back together. Easier going back in than coming out. Had a couple of small coolant leaks after install, but changing a couple of the spring heater hose clamps for worm clamps took care of the issues.

Additional things I learned.
1) No need to drain all of the coolant. Just suck out the coolant in the expansion tank ( Turkey Baster), There will be a little spill from the heater core ( especially if you also decide to flush it). Total loss for me was less than 1/2 gallon. For a little more working room, remove the Expansion Tank bracket ( top bolt out, bottom bolt just needs to be loose). If you have access to the bottom of the vehicle, the two lower bolts on the Valve Bracket can be reached from underneath with a long extension, universal joint and 10MM socket.
2) Don't even think about attempting this without a good assortment of hose clamp tools. I bought the full kit from Amazon, 6 pliers plus the long reach clamp tool, plus a three piece assortment of Hose pulling pliers. Still struggled a bit. Don't scrimp on the tools- you'll use them again in the future!
3) If you don't want a delay, think about ordering a couple of additional parts in advance. 1) Throttle Body gasket. I found prices from $7 to $32. Ordering early can save you money. PN NCA3021BA for my '97.
4) Order some rubber isolation mounts. Total used are 4, if they are all bad. On mine, 2 were bad. They are 6mm x 1.0 male thread both sides, 15-20 mm long , with a 15MM long rubber body. I bought a 4 pack on Ebay ( look up Rubber Isolation Mounts M6 MM 20x15mm). There is also a Jag PN that will work, EAC6805. I found these also on ebay in a 2-pack- just a little more expensive than the 4 pack I bought, but in retrospect probably a better part and worth the extra money. If they are broken in the firewall, a deep 15MM socket can remove the broken piece. These parts will also fix that problem part that the air box / air filter box attaches to on the right side fenderwell.
5) The brush kit I ordered worked ( PN 14-80140). I attached a piece of 220 grit wet / dry sandpaper to a hand held sanding block. I held the block with my left hand, and moved the brush up/down on the paper, measuring with a pair of digital calipers to get the proper size. 4.4 mm high x 4.4 mm wide x 9.2 mm long worked. Took about 20 minutes of hand sanding and measuring to get them where I wanted. Messy- be careful! Scribe marks on the brush helped me sneak up on the finished dimension.

To get them installed, I bent out the back edge of the brush holder, allowing the spring to come out ( be careful!). I also had to loosen the bolt holding the end of the armature. You don't have to fully remove the armature, just get it loose enough so it will move a little side to side. I noted where the brushes had been riding on the armature before releasing this nut, but it came back to the same spot without issue. I needed this extra room to be able to insert the brushes into the holders, backing them in, so that the lead would exit through the slot in the top. No way to insert from the rear. Once both installed, and the nut back on the armature, re-install the brush springs and bend down the end tab. Be careful that the spring doesn't get away from you!!! You can then proceed to solder the leads, and re-assemble everything. Once re-assembled, I decided to test it. Without water, it was noisy, and I was concerned. I then stuck the inlet hose into some water, primed the pump ( Suck on the outlet hose), and then tested again. Worked quietly!! I also applied 12V to the valve. You can see the valve operate through the coolant hose openings. Just a good test to make sure the solenoid is still working, and the valve moves freely.

6) Once everything was back in the car, and I had refilled the drained coolant, I decided I would like to try and prime the heater core a little. Wasn't sure If I could, but I applied 12 V directly to the top of the Heater Pump Fuse ( Jumper wire to the Stud at the side of the Fuse Box), and the pump started running, and the coolant immediately drained out of the expansion tank. Don't let it run too long- mine ran dry and got noisy, like on my initial test. It did seem to help some, though, as I had heat as soon as the car started to come up to temp.

 

Hi All,

I've had this problem and actually put an additional replacement pump 'in line'. The design of the pump is such that it offers no resistance to flow so the defective one can be left in situ. Whilst not elegant it is a quick and effective solution as I really didn't want to be spending hours under the bonnet last winter. I'll post a couple of pictures in due course in case anyone else is interested in this admittedly lazy solution.

However that was last winter and now I've lots of time on my hands in this better weather so if for no other reason than to keep busy I'll be following the procedure above.

What I really wanted to contribute however is how to overcome the problem EVERYONE has in taking off coolant pipes that have been attached for decades. I was surprised to learn there is a special tool that mechanics in the know use and it's described on youtube here: It's specifically used to break the seal between the rigid and flexible pipe (the tools previously mentioned merely give a little extra purchase). I made up such a tool and trust me it does in seconds what I struggled with for I don't know how long before giving up.

 

Hello sidney84,

Welcome to the Jaguar Forums! It's great to have you with us.

I have been using hose picks like the ones in your photos for several years and they are most definitely a helpful and inexpensive addition to one's toolbox. I believe mine are branded Astro Pneumatic.

Please visit the New Member Area - Intro a MUST and post a required introduction so we can learn something about you and your Jaguar and give you a proper welcome.

Cheers,

Don

 

Mine is intermittently making a loud noise, is this an indication of a future failure. This is a big enough job that I can live with the noise for now.


I just purchased a used pump off ebay for $42. If I can fix it and have it around for if I ever do the repair it may save some time, then I can fix the one I take out and put it up for sale for the next sucker.....

 

I have 2 pumps on the bench that I rebuilt.

 

Gus,

As you probably know, a new fuel pump assembly in the 4.2 cars is insanely expensive. Are you capable of rebuilding them?

 

I would need to play with one that has been removed to see what I can do.

Gus
JagRepair.com - Jaguar Repair Information Resource

 

I bought a set at Harbor Freight...
Don't tell my Jag that though.

 

Hi all,

In addition to all contributions in the previous years
on this topic. I hope it might help some fellow Jaggers.

I replaced the heater pump in my '99 XK8 convertible
(using the special tools I found in this thread - thanks!)
without removing the throttle body.
I even took the valve and pump out of the car
while both of them were still on the bracket...!

This is what I did:

• I raised the car a bit (so I didn't have to bend over that much)
• I didn't bleed the system, just sucked out the coolant from the reservoir (and hose underneath)
• then put a receptical under the car (for the unavoidable spills)
• then took the coolant reservoir and bracket out
• got all wiring and hoses out of the way as best I could
• then took just 4 hoses off: 2 to the valve and 2 to the bulkhead (the tools were very useful)
• then turned the 10mm nuts underneath the rubber mounts until these mounts broke (with a small spanner from the top)
• released the 2 nuts on the upper rubber mounts (they came off without any trouble)
• and finally took out the bracket with valve and pump still attached.

Maybe there's less 'room to move' in the engine bay of
an XKR or XK with 4,2 l engines so you need to remove
the throttle body, but in my 4.0 liter XK8 this was no problem
(but I still wish I don't have to do it again :-)

Cheers!
Marc

 

You dont need to go to all this trouble just fit another pump at the top alongside the expansion tank ...bosch about £40. I have written it all up on here somewhere under pistnbroke

 

I just went through this ordeal for the second time in my 2003 XK. The first time i did it while replacing the plastic wallpiece behind the engine (cracked in half).. swapped the pump out with one used unit. No help.

It turns out that it is actually three things that can interfear with getting heat in the cabin.
1) Super hard to get the air out of the heater core, most likely due the the bent hoose on the outside heatercorepipe that sticks out from the wall, its ususlly very flat and severely restricts the flow of water. That bend is on the pipe that comes with the water leaving the heatercore and first it has to somehow get pushed through that flat hoose and then push the checkvalve open in order to get through. The impeller on the waterpump is not directly connected to the electrical motor, the connection is via an magnetic coupler, if the waterway gets blocked the motor can still run... so hardly any water will circulate if its all bad..
2) The water valve gives up, coil shorts out, if it gets stuck closed (like mine) no water will circulate through heatercore.
3) Due to No.2 the driver cirquit burns out in the climate control module. (dont hook up a "new" module unless the watervavle is checked ok, or replaced with a good one)

This time i had armed myself with a complete assy with the watervalve, pump, and all the hooses nicely disconnected from a donor car. (got it at RRR.lt)
First i used a pump and sucked up all coolant from the system.. loosend a radiatorhoose in the front and kept going.. With coolantbottle and its bracket out of the way, i first disconnected all heater hooses, removed contacts and the four nuts to the bracket, twisted and turned it for an enternity... then it came out.
While at it, i also replaced the plastic thermostat housing to one in shiny aluminium.

When assembling all this, i first had the electrical waterpump checked in a bucket and made a mess.. water everywhere.. :-) and the watervalve i just checked with a 12volt battery and made sure it clicketiclocked nicely. After installation i kept the watervalve disconnected (my climate mudule is fryed).
The in my opinion, the to much bent hoose, that goes to the heater core, got replaced with a new one i ordered after going through 18 pages of coolant hooses in order to find one with the right bendradius, trimmed as required to make it it fit and installed it.

Now we are talking, after pouring back all the coolant and the engine running for 2-3 minutes i got the precious heat in the cabin. With the watervalve contakt dissconnected, the watervalve will grant access for fluid to circulate through the heatercore.

All good, now i need to find myself a climate control module and replace that one too, or see if i can repair mine.. if i just can figure out where it is located..

-In the descriptions i have come to realise that it is supposed to be installed a "heatsheild" in front of the watervalve, does anyone have a picture of what that looks like? I have never seen one..


My new shiny aluminum thermostat housing.

 

Seems the 'water valve heat shield' (MJA6731AA) is a ghost. Mine doesn't have one, the late XKR I'm attempting to resuscitate doesn't have one and I've never seen one either.

Heritage, however, can sell you one for a modest sum :
https://parts.jaguarlandroverclassic...eatshield.html