Troubleshoot hydraulic pump flow

440roadrunner · January 14, 2011, 12:28:37 AM

On my little ?? Cleota, using an old belt driven pump, it's finally apparrent that the hydraulics are getting SLOW. I had a internally bypassing cylinder which I fixed, and now it holds "up" in good shape. the pump generates enough pressure to lift the front end of the crawler on downpressure, and the belt drive will squeal at full cylinder travel.

I do have a suction filter, forgot, but specifically asked for "big" micron spec because I figured this old system needed all the slop it could get.

I suspect the filter may be getting plugged, although I did run it awhile when first installed, then changed the filter. This was before this trouble began, which has just be sometime lately My memory thinks there may be test taps on the filter. If so, what max suction should I expect, each side of the filter? ------

and how else can I go about this?

Pump does not lift far, maybe 1 foot. Suction line is about 3, maybe 4' of 3/4 hose, double braid. All pressure hoses are 1/2"

http://cletrac.org/forum2010/index.php?topic=2321.0

Best picture of the hydraulics I have, this was before I installed the filter on the line coming out the lower right (front) end of the tank:

In the shot below you can see the pump, and that it doesn't lift much. Am I thinking correct, that since it still develops pressure enough to lift the cat off the ground that the pump is not internally bypassing?

Tim Ling · January 14, 2011, 03:12:57 AM

Look and see if there is a test port on your hydraulic valve, where you can tap a gauge into and check main relief pressure. You could also connect a gauge in line at your lift cylinder and check pressure there. I feel that if the blade will lift the front of the tractor in the down position, that you are getting adequate pressure and the pump is not at fault.

John Schwiebert · January 15, 2011, 03:13:12 AM

Filters on the suction side are not good news. A strainer is O. K. A filter should be on the return side. Also do not use pressure hose for a suction hose. How large a cylinder are you using? A poor mans flow rater is to know the volume of the cylinder and then the time to extend it. Then do the math and convert the output to GPM.

hotratz · January 15, 2011, 03:59:13 AM

Quote from: John Schwiebert on January 15, 2011, 03:13:12 AM
.......Also do not use pressure hose for a suction hose..........

John, could you elaborate on this a little?

440roadrunner · January 15, 2011, 04:42:56 AM

Quote from: John Schwiebert on January 15, 2011, 03:13:12 AM
Filters on the suction side are not good news. A strainer is O. K. A filter should be on the return side. Also do not use pressure hose for a suction hose. How large a cylinder are you using? A poor mans flow rater is to know the volume of the cylinder and then the time to extend it. Then do the math and convert the output to GPM.

Ya know it just never occurred to me that I could put this into the return!!!

I haven't had time to deal with this more, I've been thinking of (temporarily) just yanking the filter out of the system. I guess it'd be a good time to replumb!!

Also, tonight I may have run into a buy on a pump, I'll have to find out if you can belt drive it:

http://spokane.craigslist.org/tls/2161196157.html

John Schwiebert · January 15, 2011, 12:13:25 PM

It is your money. I don't know what pulley set up you have but a lot of smaller trucks (trucks with automatic transmissions and no provision for a PTO) with snow plows have belt driven pumps and with a clutch similar to an airconditioner clutch. Also remember pump output is theoretical. Use 80-85% of theoretical output for actual flow. On the suction hose, you need a hose that has support on the inside either when the hose was formed or it was installed after the hose was manufactured. On filters for a gear pump a 30 micron filter on the return side is good. A 100 mesh strainer is good on the suction side.

440roadrunner · January 15, 2011, 04:16:58 PM

Quote from: John Schwiebert on January 15, 2011, 12:13:25 PM
On the suction hose, you need a hose that has support on the inside either when the hose was formed or it was installed after the hose was manufactured.

I was thinking last night, maybe find some big long springs (can stretch them out longer) and slip inside the suction hose.

Lord, I hate to tear all that stuff down, probably won't be until winter leaves us here

LoggerLee · January 21, 2011, 06:42:52 AM

Heck man it was dang near 60* here beginning of the week,winter...haha
Heard there was some snow up there tonight.

hotratz · January 21, 2011, 08:08:47 PM

Quote from: John Schwiebert on January 15, 2011, 12:13:25 PM
On the suction hose, you need a hose that has support on the inside either when the hose was formed or it was installed after the hose was manufactured.

Well I guess I'll need to keep an eye on my suction hose. You learn something new every day don't cha'

440roadrunner · January 22, 2011, 01:33:47 AM

Quote from: LoggerLee on January 21, 2011, 06:42:52 AM
Heck man it was dang near 60* here beginning of the week,winter...haha
Heard there was some snow up there tonight.

It doesn't know WHAT to do. It's thawed, froze, snowed, thawed so many times this year that I can't count 'em. Thawing, raining, and just above freezing (wet) MAY just be harder on my arthritis than colder and dryer.

digitalhaze · February 19, 2011, 08:37:09 AM

I have trolled these forums occassionally the past few years in the hopes of someday rebuilding my oliver. Got a bit excited when i saw this post, because it is the only other OC-3 I have seen with the holt blade. I am clearly lucky that my OC-3 remains completly unmolested after so many years. I was told by the local antique tractor expert that my blade was home made, he even claimed part of it was made from a piece of pipe, which i disputed. I am not even sure where I am going with this post, or why it would matter to anyone else, but here are a couple of photos of what should have been the original configuration.

hotratz · February 19, 2011, 04:49:11 PM

dhaze, Welcome to the forum. If you hang around long enough you'll learn of quite a few with Holt blades. You tractor does look like it was kept pretty original. Pictures are always welcome, thanks. This post is a great candidate for the "New Members Introduction" section.

440roadrunner · February 27, 2011, 05:18:08 PM

Hi, digitalhaze. Your Holt appears completely different from mine, but I believe mine to be "hacked." May not even have the correct blade. Here's my progression post of "how it went:"

http://cletrac.org/forum2010/index.php?topic=2321.0

If you go down through and wait for the photos to load up, you can see how mine appears to be fabricated. It was only this winter that I discovered the angle clamps --obviously hacked up-- were nowhere near adequate. I'll probably "pin" the blade angled one way and make at least one more clamp and just leave it there. SURE WISH MINE was the narrow track like yours. It's a real chore to get mine on the trailer!!

And I STILL have not turned a wheel on the hydraulic problem. This week was VERY cold, and as "we speak" it's only about 22F and slowly warming back up from Neg F overnight.

Crazy Matt · March 15, 2011, 05:18:10 AM

Wonder if your hydraulic pump is going away.

440roadrunner · March 16, 2011, 02:57:26 AM

hi, Matt. I don't think it's the pump. as you know, the wx hasn't been good, and what little good there is, I've been overworked. Just today hauled off a junked out 77 Dodge van to the wreckers. I'd bought it for 350.00 for a "quickie" driver engine (360) and Torqueflite for the new Dart while I go through the "real" 360

Anyhow, I just have not had time or wx to pull it down. I'm pretty sure at this point the filter is starting to restrict the pump, and may have damaged the suction hose.

I don't know what in 'll I'd do without that chassis hoist. Dropped 'er right out the bottom