Hydraulic Relief Valve Adjustment for Bx2230 and Bx1830

[Kerton]

By the way, to offer a bit of help to others in my position, I have located the part numbers in question from my BX 2670 parts schematics:

31351-37970 110 SHIM 0.10mm
31351-37960 110 SHIM 0.20mm
31351-37950 110 SHIM 0.40mm

And, yes, using the parts numbers, those can be web ordered from Messicks. I did order them just now, but as an example of my complaint, shipping for those tiny shims is $14, and it'll still take longer than I want to wait and I have no idea how long that will be. Amazon Prime, in contrast = 2 days.

I ordered a few extra, so if anyone on the West Coast wants one in the future, they can hit me up and I may be able to priority post it to you at cost.

 

[Tractor Seabee]

Even .4 mm is pretty thin. Others have posted they used washers but that would only work if you were raising the pressure a lot. At 39 PSI per .1 mm. When I raised my pressure from 1780 to 2000 it only took .5 MM. The diameter of the shims is 12 mm, some have holes in them and some don't. A SS fender washer I have measures 1.4 MM thick. They were so cheap I bought extras.

Ron

 

[Kerton]

The shims arrived from Messicks, USPS First Class mail. Order 5/25 arrived 5/29. Pretty good shipping, of course they're tiny, and it was "mystery shipping" until it arrived. USPS First Class is supposed to be trackable and 3 days, but you don't get a tracking #. And my calculations at the USPS show that it should cost about 91 cents to mail, but I paid $14. I know there is some "handling' involved, but c'mon, $13.09?

I have documented the shim specs for those interested, and basically confirm what Tractor Seabee said above. They are 12mm diameter, and look like this:



I put them side by side with some common objects for comparison. Three shims are on the right. I think somebody clever could find a way to jury rig their own shim if they wanted to. The biggest challenge would be to get it thin enough, evenly across the surface.

 

[Kerton]

Hydraulic Relief Valve Adjustment for Bx2670 or similar

Well, I put my shims in. I tested out to 1725 lbs stock with 45 hours on my BX2670. There were no shims out of the factory. I put in one 0.4mm shim and tested out to 1925 lbs. I'm gonna leave it there for the extra kick, for what its worth. The math works out to 50 lbs per 0.1 mm on my job, not the prescribed 39, but I supposed it's not a precise game.

The job is different than described in this thread for those of you with a later models, like the BX2670. For one, you don't need to remove the rear left tire at all. I did, but realized it was totally unnecessary. The whole job is easily accessed from behind.

Here's what it looked like from the wheel side:

Above, you see the slider for the lawn mower lift system, and just behind it, the hydraulic limiter bolt. It would be pretty hard to access it from the tire side.

These next two photos show the limiter from the rear.

The spring is located behind the lower of the two visible large bolts. Use a 7/8 or 22mm socket to take it out. Be careful the spring doesn't fall. Don't worry about oil. There is no pressure here with the engine off (but I did lower my bucket and relieve any system pressure just in case.) I also hosed the area clean a couple of hours before I started, to keep the dirt outta my hydraulic fluid.

The reason I have those chains is that I took off one of my lifters to check into a metal shop welding a hydraulic tilt. One chain is temporarily substituting for the lifter. The other chain is a drop limiter for my Quick Hitch QH, so I can either set a consistent height for ground work, or keep the QH from dropping too low when I'm mowing with the mmm.

Below, you see the bolt and the spring, on the WSM printout from CHDinCT.


The last photo shows my end pressure after inserting the 0.4mm.

Looks like a nice 1925 lbs per sq in.

Total job time once you have the parts, 5 minutes.

I've got 5 dump trucks of recycled asphalt and a rented rollingcompactor coming tomorrow. We'll see how it lifts.

 

[Kerton]

One last question. Anybody know how high to torque the limiter bolt when re-installing?

 

[sandyc]

I'm just sitting here and reading/absorbing the information......while I am not sure what my pressures are on my B I would hesitate raising the pressure too much as I would not want to run near the bursting pressure of a line or seal in one of the cylinders. Just saying!

 

[CHDinCT]

Nice write up. I did mine about a month ago. After 3+ years of good usage and over 400 hours, my un-adjusted pressure was at 1,700. That was down from around 1,775 when new as I recall. Added .3 mm of shims if I recall correctly and ended up at about 1,900 psi. Good enough for now. I really haven't done anything too demanding to notice the difference so far.

As far as hitting the burst pressure of the system, the hoses are rated at 3,000 psi IIRC, which should be the weakest link. You won't hit that from raising the relief pressure cut off, but you might if you induced a shock load, like having a load in your bucket and dropping it fast, then stopping it quickly. That would spike the pressure in the FEL lines and it would not make any real difference if your relief is set at 1,750 or 1,900 in my opinion.

 

[ajry]

hydraulic relief valve adjustment for l3830, instructions and pics if possible

 

[Tractor Seabee]

hydraulic relief valve adjustment for l3830, instructions and pics if possible

The Work Shop Manual for your model provides all the info we have been discussing for our BXs. If you plan to any work other than maintenance outlined in the Operator's Manual you need the WSM; I have paid for mine several time over in the last 5 years avoiding trips to the Dealer shop; besides, just learning how things work. The WSM is only available through Dealer Parts Counters and usually have to be ordered. Messick's will be glad to send you one at their profit making shipping charges. I just waited the 2 weeks it took my Dealer to order and get with their next parts shipment. I only wish it was in PDF format.

Ron

 

[Kerton]

hydraulic relief valve adjustment for l3830, instructions and pics if possible

Wait...Is that really the way you pop in and ask for help?
In a thread where we're talking about different tractors?

Man, if anybody treats me that rudely and expects me to help, they'd better be paying me well.

We all have problems we need to fix with our tractors, sometimes in a rush. But so long as you're just dropping a question in the wrong forums, why not write a polite one just once, and copy and paste it?

Here, I'll even help you. Copy and paste, starting with this:

Hey guys, lots of good information here. Thanks for sharing some of your valuable time to help each-other out. Love these forums!
I'm having a bit of a problem right now, and was wondering if somebody out there would be so kind as to help me.
Insert your problem here

Your welcome.