HOW TO: Adjust the Pressure Relief Valve (PRV) on the MF GC 1705/10/15/20

[Clipse3GT]

Thanks Ken! Couldn't have done it without your test gauge.

Hopefully next week I'll have time to mount the bolt on hooks. Do a write up for those.

 

[ray66v]

Hopefully next week I'll have time to mount the bolt on hooks. Do a write up for those.

I would strongly recommend the use of a sealer, under bolt on hooks.

Capillary action will draw moisture under them. And, the bare metal created from drilling holes, can be susceptible to corrosion.

I suggest a butyl rubber sealer, or similar one, that stays pliable.

 

[Clipse3GT]

Just an update.

Put about 12 hours thus far with the slightly increased PRV setting. No ill effects have been noted thus far. No leaks or seals blown keeps working away. Mostly done with the backhoe and snow plowing and snow moving.

 

[AxleHub]

Just an update.

Put about 12 hours thus far with the slightly increased PRV setting. No ill effects have been noted thus far. No leaks or seals blown keeps working away. Mostly done with the backhoe and snow plowing and snow moving.

Slightly off topic but related to your PRV adjustment. I noted in your description that you were working right next to the mower height adjustment know and nuts.

I and a number of others have experienced an inability to lock the mmm deck fully raused while using the 3pt.. my dealer servuce manager said it likely has to do with either an adjustment or a damaged nut from the factory.

So when I take tge tractor in at initial service (50 hour service which will end up being 80 hour).

My question is . . from where you were working . . can you access and adjust that assembly for the mid lift lock lever? If so, I'd consider having them check and adjust the PRV valve at the same time.

P.S. It seems strange . . . With my deck on the lock doesn't work . . but with the deck off . . It does . . . so weight on the lock mechanism seems to influence it.

 

[Clipse3GT]

Slightly off topic but related to your PRV adjustment. I noted in your description that you were working right next to the mower height adjustment know and nuts.

I and a number of others have experienced an inability to lock the mmm deck fully raused while using the 3pt.. my dealer servuce manager said it likely has to do with either an adjustment or a damaged nut from the factory.

So when I take tge tractor in at initial service (50 hour service which will end up being 80 hour).

My question is . . from where you were working . . can you access and adjust that assembly for the mid lift lock lever? If so, I'd consider having them check and adjust the PRV valve at the same time.

P.S. It seems strange . . . With my deck on the lock doesn't work . . but with the deck off . . It does . . . so weight on the lock mechanism seems to influence it.

There is no easy access to get to that adjustment when you get under the tractor. There is a couple of other items that have to be removed to get to that locking system. Removing those 2 small bolts to adjust the PRV will not cut it.

I have the same issue with my GC1720. It does not lock in place with the mower deck on. My dealer ordered a new part (not sure which one) that he will modify per MF specs in order to have the unit lock the mower deck in the up position. I will stop by my dealer next week when they plan to send a mechanic up to replace the part. I'll try to take some pics of the mod as well.

 

[AxleHub]

There is no easy access to get to that adjustment when you get under the tractor. There is a couple of other items that have to be removed to get to that locking system. Removing those 2 small bolts to adjust the PRV will not cut it.

I have the same issue with my GC1720. It does not lock in place with the mower deck on. My dealer ordered a new part (not sure which one) that he will modify per MF specs in order to have the unit lock the mower deck in the up position. I will stop by my dealer next week when they plan to send a mechanic up to replace the part. I'll try to take some pics of the mod as well.

That would be good Clipse . . I have noted a fair number of GC owners seem to have the same issue as you and I. And it would be nice to know if there is a new part that has to be ordered by the dealers . . but know about it ahead if time. When I take mine in . . Its a couple hour drive each way. An overnight us one thing but I wouldn't want to get it there in March and find out it would be 2 weeks being there waiting for the part for warranty fix.

 

[Fiziksgeek]

Got my gauge and checked the hydraulic pressure this past weekend. I read just shy of 2K, figured it was good enough for me, so I decided not to adjust it!

 

[DJRussell]

First of all, thank you all for an excellent writeup on how to adjust the pressure on the GC 1700 series. I have about a 7 year old GC2610 that I have owned for about 3 years. I have levelled about 1 acre of hilly land, rototilled the same, dug out hundreds of poplar tree stumps, and the machine is great.

Last week, moving about 3 tandem loads of dirt, I noticed the loader was straining to lift a full bucket. I remembered this thread, and went out and bought a 3500 psi pressure guage and tested my loader pressure, as per this thread. I had only about 1300 psi. The adjustment procedure was almost identical, but did not have the same bracket to remove (no 14 mm wrench needed). I was able to adjust the set screw through the opening for the mower deck height adjustment.

I increased the pressure with approximately 1/4 turns on the set screw, each adding about 200 psi, and fine tuned it to 1900, or very nearly the 1920 spec for the GC2610. I have not had a chance to give it a workout, but it surely must be better now, changing from 1300 to 1900 psi.

Thank you once again for an excellent writeup, complete with great pictures.

Jim

 

[AxleHub]

First of all, thank you all for an excellent writeup on how to adjust the pressure on the GC 1700 series. I have about a 7 year old GC2610 that I have owned for about 3 years. I have levelled about 1 acre of hilly land, rototilled the same, dug out hundreds of poplar tree stumps, and the machine is great.

Last week, moving about 3 tandem loads of dirt, I noticed the loader was straining to lift a full bucket. I remembered this thread, and went out and bought a 3500 psi pressure guage and tested my loader pressure, as per this thread. I had only about 1300 psi. The adjustment procedure was almost identical, but did not have the same bracket to remove (no 14 mm wrench needed). I was able to adjust the set screw through the opening for the mower deck height adjustment.

I increased the pressure with approximately 1/4 turns on the set screw, each adding about 200 psi, and fine tuned it to 1900, or very nearly the 1920 spec for the GC2610. I have not had a chance to give it a workout, but it surely must be better now, changing from 1300 to 1900 psi.

Thank you once again for an excellent writeup, complete with great pictures.

Jim

Quick question. The GC2610 was working fine before I assume. What would have happened to cause the presdure to drop from 1900 to 1300 ? I ask this because apparently it was not a leak . . Because if that was the case after you adjusted it . . it would have bled down to 1300 again. Any ideas or input ?

 

[DJRussell]

I have been working the tractor fairly hard over the last few years. I bought the tractor 2nd hand, and it seemed to work fine at the time, but I didn't measure the pressure output. I believe over the last few years, the pressure relief spring may have weakened gradually, and left me with the 1300 psi. Just my thoughts, I really don't know. Now that I have the pressure guage, and the knowhow to check the pressures, I will do this annually to monitor the pump output.

As I mentioned in previous post, I haven't had a chance to give it a workout since adjusting the pressure, so I really don't know if there might be other problems with the pressure relief valve.

Jim