Farm Equipment - Hydraulic pump and ram capacity

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Hydraulic pump and ram capacity

Printed From: Unofficial Allis
Category: Allis Chalmers
Forum Name: Farm Equipment
Forum Description: everything about Allis-Chalmers farm equipment
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=209887
Printed Date: 28 Jan 2026 at 5:05pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: Hydraulic pump and ram capacity

Posted By: JTS
Subject: Hydraulic pump and ram capacity
Date Posted: 28 Jan 2026 at 9:51am

I inherited my father's WD45 and am rebuilding it. Apparently he changed the hydraulics from the back of the tractor to the front to operate a snow plow. I replaced the single unworking ram with two new large rams. (The plow is extremely heavy). I've gotten everything running and no oil pan leaks, but now I have a leak coming from behind the fly wheel cover. I believe it is either a faulty gasket between the hydraulic and bell housings leaking oil from there. Or the rams I bought are way too big for the pump to handle, creating too much pressure. I've looked in all three manuals I have and online to find the capacity of the hydraulic pump on this tractor and what size rams can be used, but have found nothing. Is anyone familiar with this or can possibly guide me in the right direction? I'm hoping the rams are too big because I'd rather not have to split the tractor to replace that gasket.

Replies:

Posted By: DSeries4
Date Posted: 28 Jan 2026 at 2:30pm

The leak is not related to the cylinders. Most likely the input seal on the torque tube needs replacing - could also be the rear main on the engine. Either way, you will have to split it.

Those new cylinders are probably not going to work. The hydraulic system is a high pressure/low volume set up. New cylinders are the opposite. This means they will move very slowly. Stick with the original cylinders that were made for the tractor. They will work well and are very strong!

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'49 G, '54 WD45, '55 CA, '56 WD45D, '57 WD45, '58 D14, '59 D14, '60 D14, '63 D15D, '66 D15II, '66 D21II, '67 D17IV, '67 D17IVD, '67 190XTD, '73 620, '76 185, '77 175, '84 8030, '85 6080

Posted By: DrAllis
Date Posted: 28 Jan 2026 at 3:34pm

The hydraulic sump only holds 6 quarts of oil to begin with. If you have two double acting rams larger than 1 1/2" you might be overfull of oil and it is leaking out the vent hole, which happens to be inside the bellhousing above the clutch shaft. Check the hyd oil dipstick while rams are fully extended AND fully collapsed. It can't be overfull or it will leak.