I think after many years of service, my 450C has finally exceeded its duty. It barely turns over, when it actually will turn over. In the multiple years I’ve had it, it has been used almost daily…and has been a very strong pump. I am very happy with it, but I’m sure its needing a refreshening.
Anyone rebuilt their own? I know its a pretty simple pump…and likely to just need a new piston. I know also to check the brushes…anything I need to keep an eye out for? Anyone have a good source for replacement parts? I found a fella on ebay that sells pistons for about $50 + shipping, just wondering if there might be a better source or even someone with better pricing out there.
Got it off and apart today. When I took the jug cover off of the piston (equiv to cylinder head), I heard some compression leak…so that was a good immediate sign that the piston and the jug (cylinder) were good. Confirmed that when I finished the piston disassembly, it all looked great. So I separated the motor cover from the end plates to check the brushes. To be honest, I have not been inside enough electric motors to know if these brushes are indeed in need of servicing or not…anyone know?
I see no obvious signs of damage or anything needing repair, minus the possibility of the brushes themselves.
Piston looks OK. My first guess, looking at that motor would be residual dirt, which affects contact through the brushes, but more so the bearings. Give everything a good clean out as best you can and check your bearings to ensure they spin freely.
With the motor you could check the resistance across the winding. It should be extremely high, but without knowing the exact figures to use as the baseline for that motor, it wouldn’t tell you all that much.
The part leading off the lower brush (in your last pic) is probably the thermal overload protection, but since the motor is running you shouldn’t need to check that. There should be a capacitor in there somewhere and that’s something I probably would check to ensure it’s not damaged.
As I said… my guess will just be dirt build-up or failing bearings.
clean the copper part on the rotor with steel wool or a red scotch brite to make it back to shinny copper. then sand the brushes a bit and put it back together. thats usually all any electric motor this small needs
Thanks guys. I think from the help Viair gave me via email, and between a couple of forums…I’ve determined that the pump itself was probably fine. Not sure if I had a bad ground or power supply, but one is surely not sufficient. I believe I am likely getting ready to purchase a new vehicle, so at least the timing is right for an issue. Of course, the P3’s are going on the new truck.
