Case 1150b dozer

[miller125]

I have 1150b that will lose pressure after about 1 hour checked all line for leaks
Put a mechanical pressure gauge in place of the dash mount one It will hold 260 ish
When in gear (hot) it drops to 0 when shifting from fwd to rev or lo to high My question is the moderator valve I have the old style with sims I think it’s weak cause you can pat fuel and pressure instantly jumps to 260 so do I have to have case’s special weight to check it.





I have read all posts on here guys are very Knowledge thanks

 

[Coy Lancaster]

You can shim it up by trial and error. You also may want to check the transmission pump.

 

[Vetech63]

I believe there is a transmission suction strainer on those. It rarely gets cleaned or replaced because it isn’t easy to get to. You will need to remove the belly pan under the driveshaft to access it easily.

 

[miller125]

Sorry guys all filters new and clean with fluid and new charge pump the old had wear. Trying to bring old machine to life it sit for 9 years

 

[Coy Lancaster]

If you have a Case dealer close by take your modulator valve in to them so they can set it. Hopefully they won't charge you an arm and a leg.

 

[Vetech63]

If you have a Case dealer close by take your modulator valve in to them so they can set it. Hopefully they won't charge you an arm and a leg.

I believe it’s your first born now.

 

[Coy Lancaster]

I believe it’s your first born now.

Yeah probably so

 

[miller125]

Well I took the moderator valve out and took it apart to check it and the actuator spring measured 2 7/16 free spec. is 2.62
And the poppet spring was 1 7/16 free and spec. 1.50 do guys think this is causing my zero pressure when hot When shifting from fwd to reverse and pressure returns to normal when you pat the fuel
Leading to think that the spring pressure is not there to seat in spool properly
Correct me if my thinking is wrong

 

[Vetech63]

You should check your pump.

 

[miller125]

Pump is new

 

[Vetech63]

Pump is new

Sorry,I missed that. If I remember right you have that huge stacked transmission control valve bolted to the top of the transmission. I had an 1150 doing something similar from a small piece of a control valve gasket that had blown out,

 

[miller125]

So would you replace those springs or not

 

[Vetech63]

So would you replace those springs or not

I wouldn’t myself. By increasing your throttle you are increasing oil flow to the point that the flow is overcoming the leak in the system. When I have those kind of issues I usually remove the control valve and reseal it. Those gaskets get brittle over time and will start breaking up between ports and valleys that they are meant to keep sealed. I would remove the valve, clean it and reseal it.

 

[miller125]

Ok thank you for help

 

[Volvomad]

Not familiar with the valves on this but if the pressure jumps up as opposed to slowley rising with increasing with engine speed it would sound to me (and probably me only ) like a slightly scored valve or bore that only sticks when hot .
How hot ?

 

[miller125]

Hey Vetech63 I think you were right about the controller gasket it had a piece of gasket missing The funnel screen in the gauge line was very poor shape does it need to be replaced or can it be ran without it I have not got to test it yet just got back together I will keep you posted
Thank a for the help

 

[Vetech63]

I always keep screens in place if they are reusable or available for replacement. Hopefully the rebuild will fix your issue. If not, come back and let us know. Make dam sure those parts are super clean when you go back together, especially where the old gasket is stuck to the metal.

 

[miller125]

Well finally got the gasket replaced and I think it fix the 0 to 200 psi jump when going to fwd to reverse but only get 160 psi high range and 260 ish on the low range Do you guys think it could be shaft rings on the transmission on the back
Thanks for the help

 

[Coy Lancaster]

Check your seal rings on your lower shaft

 

[miller125]

Well I pulled the rev and forward on the back of transmission to check the three oil ring they are good but the case show wear in the closest ring to the transmission ( picture farthest one in)could that be where I am lose high range pressure