ZTU water pump help

[bjz]

I am having a problem getting my 37 ZTU to stop leaking. I have tried 4 different times. The first time I put the used parts with a new seal. Every time after the first I used all new parts except for the housings. I have 2 different housings I have been using but nothing is working. On the one housing I ground the surface smooth where the bushingis but the other, I left the bushing sticking out some like it was when I took it apart. I also tried pumping more grease in but its just not working.

 

[Charlie Bilerx]

bjz,
Step one is to clean out the impeller well where the #RE522A seal package drops in. I suggest a blaster be used. If you would not lick it out after cleaning; keep cleaning. The seal boot must have a clean surface on the bottom to seal to.

Next you must look at the seal surface on the pump body, where the #RE522A seal face rides on. Concentric circles are okay, as long as they are full circles. Radial scratches are a definite no-no. You can chuck up the pump body and remove about 0.010" worth of metal to make the surface true. Do not break the edges after turning. Definitely, never just file the surface flat. Nobody can file a seal surface perpendicular to the shaft well. How did you 'grind' the iron seal surface? The seal surface should be cut with an M2 or T15 cutter bit with positive rake. Even a carbide tool with negative rake will leave a poor sealing surface on that grade of iron used for the pump body. If the seal face is trashed, you can cut the pump face away and install a replacement seal face. Do not use a ceramic face. Use a sintered iron replacement face.

Never ever place any lube on the sealing surfaces. Oil based lubes will ruin the rubber boot and any lubes will stop the phenolic sealing face of the #RE522A assembly to seal. The word is dry, when you are assembling the pump.

Never let the bronze bushing protrude beyond the sealing face. Bronze and phenolic do not play well together. The bronze will ball up on the seal face and not allow proper sealing.

What type of seal assembly are you using? The really old seal assemblies use just a simple ring to seal on the shaft, and not seal on the bottom of the impeller well. We experimented with these early RE521 and RE522 seal designs and found out they were no good. That is probably why Moline dropped them about a year into production of the RE engine. Is the spring on your seal assembly stainless, or is it the coated flavor? Some of the cheaper yellow zinc chromate springs lack enough tension to push the face tight. Does your seal look like the one in the attached photo?

When assembling the pump; do all assembly dry. It is okay to put a drop of C5A anti seize on the shaft, just before you press on the impeller. Never let that copper stuff get near the seal. Toss the old tapered pin and drive in a new #RE587-S (S=Stainless) spring pin. Most of the damaged impellers, and pulleys, come from reusing the old taper pins.

Good luck.
Charlie

 

[Charlie Bilerx]

Here is the photo I forgot to attach.

 

[MMDEL]

Charlie has given you some excelent technical advise. All I want to add is the fact sometimes a new rebuild will leak slightly until the seal and the pump surface lap themselves together and mate.
MMDEL

 

[Anonymous-0]

I have a 1946 RTI with the same problem..I have been considering pulling the pump and sending it to someone to rework...any suggests who and what would be a resonable price?

 

[bjz]

Thanks for the help Charlie. I got my grandpa to take the surfce down. He took it down 0.004" and it and it was not leaking for the 20 minutes we ran it tonight. For the moment I am leak free on the whole tractor. I am going to paint this week some time. Thanks.