420c with 90 loader

jimbobz99 · Post by **jimbobz99** » Fri Oct 28, 2016 5:12 am

Hi,I have a new (to me) 420c with 90 loader and a custom 4 way bucket.
The 4 way works fine clamping it will stall the engine if you clamp to much.
My problem is the loader only lifts the crawler a couple of inches,seems to cut relief valve,tilting the bucket will raise a little but when you release the pressure it drops back. like air in system.Where do i start to fix this.
Oil is good,bucket has separate control.Seems to be in series.Thanks

Post by **Lavoy** » Fri Oct 28, 2016 8:43 am

If it will stall the engine, I am guessing the valve is plumbed wrong, you should hear a squealing as it bypasses.
Lavoy

jimbobz99 · Post by **jimbobz99** » Thu Nov 03, 2016 6:12 am

Thanks
I was looking over the control valve it appears the relief valve
has been adjusted. I will need to find out how it should be adjusted.I think maybe they have it set for too much pressure and not bypassing.

Post by **Lavoy** » Thu Nov 03, 2016 9:30 am

I would be afraid that it is not bypassing at all. Either way, get it fixed, you wouldn't want to blow a pump.
Lavoy

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