Cheap Fix for Auxilary Coolant Pump- No Heat at Idle

02LincLS

Dedicated LVC Member
Joined
Feb 26, 2008
Messages
1,227
Reaction score
17
Location
N/A
Got around to replacing the aux coolant pump to fix my low/no heat at idle. Pretty easy job, just take air intake tube off and the "T" shaped coolant line right by the radiator and its right there. Thanks to this board for helping me know what to fix. Bled the system and all is like new again.

I decided to dissect the old one and the only thing wrong with it was the brushes on the electric motor. I got an open resistance reading after removal so I popped it apart and put the brushes back in place (used fishing line to hold the springs back off the brushes while putting it together). I got 3.5 ohms and tested it in a bucket and it works fine now. Sure is a lot of money to spend, even when doing the job yourself, for a couple of bad brushes. I'll try to find if they can be purchased somewhere.
 
Found brushes that will work...

http://store.eurtonelectric.com/brushlowvoltage33e-2-2.aspx

The length is a little long (anything under .50 would work) but could easily be sanded down. You may also need to add a small notch on the back to keep the spring centered. Otherwise, the .20x.20 is the exact size of the brush in there. They show the wire lead on the top, which matches.

IMG_20101115_155350.jpg
 
Auxiliary coolant pump fix

Hi all,
I also attempted this fix, as I am a tightwad and like tinkering. I located brushes from McMaster-Carr, item #65705K49. I actually did this repair while the pump was still in the car, not for the faint of heart or those without patience. There are 3 sets of tabs on the metal housing that hold the end of the motor in place. Pry these tabs out a bit and you can remove the end of the motor. I was then able to clip the wires of the old brushes and solder in the new brushes.
Now, I had a few challenges getting things back in place. I used dental floss to hold the brushes back far enough to slip the assembly back into the housing. The first time I tried reassembly, I actually pinched the wire of 1 brush in the metal housing. It was at this point where I realized that the brushes were a tad too long. I dremelled off a little less than 1/8" from each brush. This kept the brushes away from the metal housing when I held them back with the dental floss. Kind of hard to explain, but I slid the floss down the face of the brushes as much as possible, so as much of the brush would touch the motor rotor as possible. I also held the brushes back so that they were still "sprung" by the springs tensioning the brushes. I did this so the springs would take over when I broke the floss. I left a few inches of floss on each brush to hang out after assembly into motor housing. As I was re-inserting the brushes/motor end assembly, and at the point where I knew the brushes had made it past the rotor, I pulled on the floss that I left hanging. I also wiggled the motor end and tried to break the floss. I was able to break the floss for sure on one brush, but was unsure of the other brush. I did some continuity testing to make sure I had continuity between the brushes, but not to the metal motor housing. I figured, worst case, the spinning motor would wear through the floss.
All was good, and I fired the car up, but no joy. I had inadvertently carbon monoxided myself whilst testing the car in my garage, so I did not think things thru fully. When my head cleared the next day, I recalled the housing getting super hot when I tested it after the first assembly(when I pinched the brush wire). This blew the 10A fuse in the engine compartment, fuse #1. I replaced the fuse and the pump immediately started spinning. Yay me!
Anyway, I hope this helps. I spent $12 on parts and shipping, a few hours of my time, and the satisfaction knowing my LS has not beaten me yet. Yet.
Thanks to all the other posters on this site, I would not have been able to do it without you.

-Febtober
 
Congrats and huge thanks! This job is getting to the top of my to-do list.
 

Members online

Back
Top