NH 757C Slow Hydraulic Movement

J_J · Jul 8, 2013

What he heard, the rushing sound, was probably the valve relief going off.

I would be interested in the pressure while using the bucket to just open and close with no load..

It takes very little pressure to just move the bucket, but if digging causing a load, then the pressure will increase with more load until the relief goes off.

You can easily see that on the hyd gage in conjunction with a sound.

Powerhorse · Jul 8, 2013

J_J,

I got the replacement hoses today but most likely will not get to work on it till the weekend. Work keeps me running. The supply and return hoses are connected to a block which is also tied to the loader control valves. This is a factory setup from New Holland. The rushing sound was at the bucket cylinder not at the control valves like when under load. I'll post a pic of the block tomorrow sometime.

Thanks for your help

Powerhorse · Jul 8, 2013

Forgot to add the hoses on the BH are original. NH went with 1/4 for some reason.

RickB · Jul 9, 2013

Powerhorse said:
Forgot to add the hoses on the BH are original. NH went with 1/4 for some reason.

Just about any BH fitted to a CUT has 1/4" hoses. A very few might use 3/8". None that i am aware of use 1/2".

Powerhorse · Jul 9, 2013

The supply and returns are 1/2". I figure NH did this for volume when operating more than one function at a time. I took these pics this morning. I'm wondering if the fitting with the 3 on it isint the issue as it looks double crimped....

wdchyd · Jul 9, 2013

It's pretty obvious someone doesn't know how to crimp hoses.....I'd be leary of all of those, you may need to check them all for overcrimp

Don't forget on a 1/4" hose fitting the inside dia of the hose fitting is 1/8" or less due to the stem wall thickness....not much room for error

J_J · Jul 9, 2013

Try putting a 1/4 rod through the fitting and hose. Probably can't, closer to 3/16 in.

Everyone should know why you try and match hose size with the GPM's, and we know why loaders, BH, and anything you want to reduce the speed of operation, you use smaller hose or restrictors.

The 1/4 in hose and fittings also cost less.

If you switch hoses around, you can tell if a hose is restricted more than it should be.

Make them fix what you don't like.

RickB · Jul 9, 2013

I should have been more concise, I meant 1/4" hoses between the valve and cylinders.
Those hoses appear to me to be overcrimped; #3 especially, but also #4. Just an observation from a guy that makes Weatherhead Hoses using 425 series hose.