AC 190 hydraulic issues

Hi everyone just joined the forum. Looking for some advice on my Allis Chalmers 190 with low hydraulic pressure

when bought the tractor it had been sitting for 5 years. It has 3900 hours gas engine. I just got it running and

now it runs and drives good.

however the hydraulic linkage was stuck so I freed that up. I tried to lift a 5x6 round bale on the three point and it
would not lift. it did not even pull the engine down so I changed the hydraulic filter and filled oil. power steering works and so does the power director. I already pulled both the relief valves on the valve stack they were clean so I reinstalled both of them. still won't lift bale. if I understand correctly the front relief valve is for the traction boost and the back one is three point? so does the relief vale need new seals or swap or something. or is the pump possibly going out.

thanks

The relief valves are adjustable. A quality gauge plugged into one of the remote outlets will tell you what you have now and later, after you have adjusted it. 2300 psi is approximately what you want. Half a turn at a time with the screw. You don't want to overdo it.

Don't forget to check the sump screen under the tractor. When I bought mine is was really dirty and obviously had not been cleaned for a long time. After cleaning it and swapping valves, although it helped, the pump was in dire need of a rebuild. Sent it to SLI for a rebuild and luckily they was able to rebuild it. Now it works great. My good friend just had to purchase a new pump for his series 1 as his could not be rebuilt. $2,800, I hope a valve swap fixes your issue. Rebuilt his valve since it kept sticking but unfortunately the pump was the issue.

Edited by AC720Man - 17 Apr 2024 at 10:24pm

hey everyone here is a quick update on the 190. I took out both relief valves and opened them to inspect the orings. on both of them they were completely worn out and cracked. where would you recommend getting new ones. I did find part number (70276323) are these the right seals? also 100 bucks seems like a awful lot for some orings and other parts anyone have any good sources to get these cheaper? thanks for everything

okay thanks

When I rebuilt the relief valves on my 180 I just used the ones out of my O-ring kit. That was about a year ago and it is still working great.

There is at least ONE split back-up ring and you aren't going to kind that very easy. They are not  "cheap" quality Orings.

I don't like their prices either, but how much screwing around does one want to do to try and duplicate the correct parts ???

As with ANY relief valve rebuilding, I never change the adjustment screw from where it was unless pressure testing reveals otherwise. Ease a remote lever (with 3000 psi gauge plugged in) into engagement SLOWLY ( at 2,000 RPM) to see what you have and do NOT exceed 2200-2300 psi or you will explode the hydraulic pump.

I think most on here have "their issues with AGCO".  However, at the end of the day and when all is said and done, I am so grateful they are still here and servicing 60 year old tractors.  Not all companies would do that.  Good luck and hope the repair goes well!

hey everyone today I hooked up a three point tiller to my 190. I lifted it fine its a larger one 400-500lbs. It still won't lift a round bale. do you think the relief valve is maybe just out of adjustment? if it is how would I adjust it. I am assuming I would get a 3,000 psi gauge and put it on the remotes and them turn the screw in for more psi and out for less?

thanks

thanks Dr Allis

hey all. I decided to bite the bullet and order a new relief valve from A&W tractor. which relief valve do I need to take and and put in the new one. is it the Relief valve on the back of the valve stack or front? thanks

thanks Dr allis. also the new relief valve is supposed to be pre set at 2000 psi. I assume I would still want to back the screw out and pressure test it then and add pressure little by little?

Thanks

You can't guess what the pressure is.  Like voltage, you need to measure it.  3k psi gauges are available almost everywhere.  Amzn is a good source.  I ordered a 5k psi gauge (for my D-17 hyd issue) from my local NAPA (I like to shop local whenever I can).  The fittings were the challenge.