5 ton cold start pump info

[Jersey4x4]

I have an M816 with the Cummins and it has the cold start system with the hand pump in the cab. It leaks fuel all over when it is used. I disassembled it and there are 2 o-rings on the end which I will replace and there is a brass collar at the other end which acts like a packing nut so when you tighten the cap it is supposed to compress a seal or something. Anyway what is the seal supposed to look like? Mine has nothing there to go by and there is no real info in the TM about it. Just if a leak persists to replace the pump which I have not found a new one of. any help or leads would be great. Thanks and Merry Christmas

 

[CUCVFAN]

I don't know where you might find a new one. My recommendation would be just don't use it. I've never actually had an occassion where my truck would not start with just part-throttle application. Maybe add an ether start kit instead?

 

[BKubu]

I agree with Neil. I never mess with that pump. I usually just give my trucks just the faintest hint of ether.

There is a rubber O-ring inside that has probably failed. I replaced one on my M817. I believe I bought it from one of the big dealers, probably CSI. Good luck!

 

[jcappeljr]

The Cummiins are cold natured,A sniff of ether helps alot.

 

[73m819]

just replace the o-rings, the fuel is leaking past the o-rings been there, done that

 

[Jersey4x4]

just replace the o-rings, the fuel is leaking past the o-rings been there, done that

is there 2 or 3 o-rings?

I took it all apart, replaced the 2 on the end and it looked like there should have been one on the upper end also, like a packing . So I added it, lubed it all up and now it works but is a bit stiff to pump. I can max out the psi gauge in 1 pump now and if you go crazy with it you can see the smoke come out the intake for the air filter.

Anyway, I will see for sure tomorrow morning if it really works or not. we have had ice every morning this week so it will be a good test.

 

[Vintage iron]

The good thing about having a Cummins 250 is that the air intake is on the drivers side. Easy spraying of ether from the drivers seat! I am planning on putting in a pre-lube system to help with starting all year around.

 

[EMD567]

My cold start pump works great, along with the glow plug, and I use it anytime the temp is below 40º. It works well, but does make a lot of smoke starting.

 

[crasheej]

 

[cx65083]

Does anyone make a prelube kit or are they available aftermarket? I've thought of just building one but haven't found a suitable pump that'll work with cold oil AND run on 24v. Anyone have a lead on one?

 

[MyothersanM1]

FYI to all 809 owners for your part number lists:

O-rings for manual fuel pump...
Brasscraft #0562, 3/8" I.D. (1/2" O.D.) X 1/16" Wall purchased from Lowes

 

[doghead]

If you do an advanced search in the 5 ton forum, for primer o ring, there are 9 threads(that mention the o rings).


There are also 2 check balls and light springs that get gummed up, in the pump. It's best to remove the pump, to service these balls.

 

[Hooty481]

I just recently had the same problem. I thought there should have been 3 o-rings in there but there is only 2. The 2 on the end of the shaft. I think if you put a 3rd o-ring then it will be a litle harder to pump. Fuel isn't going to make it past the 2 o-rings on the end anyway. My pump maxes out pressure pretty quick too.

 

[Welder Sam]

Thanks guys. Getting ready to do a couple and this is the info i needed