B7200D Slow hydraulics....

[BlownL67]

I did a search for my question but couldn't quite come up with a good answer.

We've been getting hammered here in Massachusetts this winter and I've been working my Gravely's and Kubota quite a bit. Anywho, since I got the tractor a few years ago, I noticed the hydraulics were a little slow. Right after I purchased the machine, I replaced all the lines (rubber/metal) on the 1630 bucket and controls. Along with the lines, I did a full fluid/filter screen change and swapped over to SUDT. Everything is nice and tight and there are no leaks, but over time it seems like my bucket has really slowed to a snails pace when I am trying to operate it. The only way I can really get the bucket / loader to move is to basically lay on the gas pedal and let it work very slowly. This afternoon I had to do a quick emergency lift of one of my Gravely tractors into the back of my truck so I strapped it to my bucket and had to sit there for about 5 minutes with my foot on the gas pedal until my loader finally got to about 4' up in the area so I could self load the machine. The only part that comes to mind is the hydraulic pump. I know its a pretty expensive part, but if it fixes my problem, I'll gladly drop the money in a second! I bought the machine with 286hrs, and I'm up to 306 in the past 2yrs so I really don't rack up much for hours at all.

Any help or advice would be appreciated!


- Mark

 

[gktilton]

have you checked the stainer for the hydraulic fluid?

 

[BlownL67]

Yup, checked the strainer. Fluid level is dead nuts too. I replaced the strainer when I drained all the original hydraulic fluid back when I got the tractor and it only has about 15hrs on it since then.

Thanks for the reply though!

 

[gktilton]

Did it get this slow suddenly, or has it been getting continually but slowly worse?

 

[BlownL67]

Did it get this slow suddenly, or has it been getting continually but slowly worse?

I don't use the machine very much but I noticed over time the loader was really struggling to lift at times. I was able to stack some snow over the weekend, but it was just some light duty. Yesterday, when I tried to lift my 500lb Gravely tractor into the truck she was struggling really bad and took a good 3-4 minutes and my foot on the gas to get the bucket high enough to get into the bed of my Sierra. I deal with hydraulic systems on a daily basis working on jet fighters so this really has me thinking that the pump is slowly failing.

 

[ColdRider]

I don't know if you have power steering or not, but on my B7200 there is a block on the pressure side(bottom) of the hydraulic pump where the power steering and the loader hydraulics are split. There is a lever switch that sometimes gets moved half way shut and slows my loader down. It is used to bypass loader when it is removed from the tractor.

I have over 2000 hours on it and replaced the pump recently because the front shaft seal would not hold and oil was overfiling the crankcase. It still had plenty of pressure for the loader.

The new pump was $450 and fairly easy to replace. Hope this helps.

 

[BlownL67]

Nope, no power steering. I do have the same small lever on mine and check that frequently so I know that is not an issue. I made some calls already and both local dealers have them in stock for $410. Before I got this tractor, it sat in the same spot for a good 5 years. I'm sure sitting that long did not do the tractor any good.

 

[gktilton]

Before jumping to the pump make sure your pressure relief valve isn't stuck open. Do you have anything heavy on your 3pt hitch, does it raisenand lower ok?

 

[BlownL67]

I do have a tiller on the rear 3pt. It raises and lowers equally slow like the loader.

 

[meanjean]

Clean the filter screen again.
Highly unlikely this is the problem but it costs you nothing and doesn't take long to do.
Let us know what happens.

 

[RCtoywizard]

Don't know if this could be part of it but I had the locking nuts loosen up on the ends of the control cables that go to the valve block so the little piston plungers
were slowly un-threading the end of the cable making my lift and curl slower and slower.
I was very happy when I finally found my prob.

 

[BlownL67]

Thanks for the replies!

I think I'm gonna tackle the relief valve, transmission vent, and then grease the loader again. If those do not solve the issue, then I will look into draining the tractor then checking the new screen I had installed.

 

[BlownL67]

Success!

Well, I checked my fluid level. Looked to be a little frothy and bubbly but it was still right on the mark. Next I yanked removed the relief valve, did a quick inspection, then slid it back in and cranked it in. As soon as I fired up the machine and engaged the bucket it was very responsive! The 3pt hitch lifts nice and quick now too! Last, after I was done working on one of my Gravely tractors, I slid it into the bucket it, strapped it and raised the bucket right up without issue!

Big thanks to everyone on here! You guys saved me a ton of money!

 

[Kytim]

congrats!!! It just goes to show us that some things 'ARE' worth doing twice, or even three times! glad it worked out for ya.

Kytim

 

[gktilton]

Glad your back in business.

 

[Spina]

I have same machine same problem; but, not very knowledgable with the mechanics
Could you tell where the relief valve is?

 

[das fisch]

I have same machine same problem; but, not very knowledgable with the mechanics
Could you tell where the relief valve is?

I know it's an old thread, but I have the same issue. Where would I find the presume relief valve asked about above?

 

[cb750k8]

Hi
Under the seat and attached to the three point lift lever there is a cover with 4 by M6 bolts
An M10 spanner will fit the bolt heads, Remove the bolts and cover and the relief valve is there with a spring and some shims.
In my case the shims were broken.
Have a look and good luck

 

[crippler]

NOTE : There is also a relief valve located in the splitter block located by the pump in the one hose fitting. My hydrolics also wouldn't lift so I reshimmed the valve with a couple thin washers and it goes up now at idle instead of having to race the engine.