H. DeBruhl
Member
Hello,
Sorry this post is a bit long, I"m still trying to help my uncle figure out what’s up with his tractor!
I had posted a few weeks back about a Massey Harris 44 Diesel with an American Bosch PSB4A-80B pump not wanting to start and then constantly smoking when running. Motor is a full rebuild and general consensus was to recheck the pump timing.... Here is what we have done so far:
I had checked the timing prior to running the tractor the first time and thought the timing was correct. I must have been looking at the wrong tooth on the pump gear. I found the correct tooth and it was 180deg from where it should have been. I pulled the pump and corrected the timing. In the service manual I"m using it also states there is a pointer on the pump housing that should align with a mark on the pump drive. It is not exactly in line but very close when the gear mark and tooth line up. Tried starting the tractor and still no luck same issue as before. Upon further investigation I believe the overflow valve on the front of the pump has been messed with too. One of the possible problems for a hard to start tractor is for the overflow valve to be stuck open. I removed the small cap on top of the valve to only find a spring inside and a hole straight into the pump! Nothing to stop the fuel from flowing right back to the tank!! Can anyone tell me what should be there to stop the continuous fuel flow? Are there any exploded diagrams of the pump that I can reference? And finally is there anybody near Western North Carolina that can work on these pumps or is willing to come look at this tractor?
I"m not ready to through in the towel yet, but my uncle is ready to blow the tractor up!!
Thanks again for any help
Sorry this post is a bit long, I"m still trying to help my uncle figure out what’s up with his tractor!
I had posted a few weeks back about a Massey Harris 44 Diesel with an American Bosch PSB4A-80B pump not wanting to start and then constantly smoking when running. Motor is a full rebuild and general consensus was to recheck the pump timing.... Here is what we have done so far:
I had checked the timing prior to running the tractor the first time and thought the timing was correct. I must have been looking at the wrong tooth on the pump gear. I found the correct tooth and it was 180deg from where it should have been. I pulled the pump and corrected the timing. In the service manual I"m using it also states there is a pointer on the pump housing that should align with a mark on the pump drive. It is not exactly in line but very close when the gear mark and tooth line up. Tried starting the tractor and still no luck same issue as before. Upon further investigation I believe the overflow valve on the front of the pump has been messed with too. One of the possible problems for a hard to start tractor is for the overflow valve to be stuck open. I removed the small cap on top of the valve to only find a spring inside and a hole straight into the pump! Nothing to stop the fuel from flowing right back to the tank!! Can anyone tell me what should be there to stop the continuous fuel flow? Are there any exploded diagrams of the pump that I can reference? And finally is there anybody near Western North Carolina that can work on these pumps or is willing to come look at this tractor?
I"m not ready to through in the towel yet, but my uncle is ready to blow the tractor up!!
Thanks again for any help
