Help with quick couplers

spiceman · Mar 19, 2020

So I got a MTL grapple, but the couplers are not the same size as what's on the hoses from the diverter.

I emailed MTL, but haven't gotten an answer on the best or easiest way to fix the problem.

The diverter hoses have 3/4 in couplers with "PBV 10 M/F 3/8 NPT G6" on them.

The grapple has 1 inch couplers with "DNV 712 - M/F 08 N B19" on them.

I'm new to hydraulics so the part numbers are a bit greek to me.

THanks in advance for any advice.

Barry

ericm979 · Mar 19, 2020

The great thing about standards is there's so many to choose from!

Unfortunately there's a bunch of standard in hydraulic couplers. I think your diverter side couplers are these 3/8 couplers:
3/8" NPT ISO 7241-B Quick Disconnect Hydraulic Coupling/Coupler Set: Amazon.com: Industrial & Scientific
which are ISO 7241-B. The most common coupler on CUTS is ISO 5675. Usually in 1/2" for accessories, often smaller for the loader disconnects. While I can find a reference that says that ISO 7241-A interchanges with ISO 5675, I can't find one that says 7241-B interchanges with 5675.

The safest thing is to replace all the couplers with something that you know works. I like the Pioneer 4200". Pioneer Quick Coupling, 1/2 in. Double Acting Sleeve Set at Tractor Supply Co.
They cost a few dollars more per set than the cheapest ag couplers but the disconnect sleeve works both ways and is easier to move than most other couplers I've tried. They're easier to connect/disconnect. You may need some adapters to fit them to the hoses. Don't use plumbing fittings as they're not rated for the pressure. Use hydraulic fittings. Don't use teflon tape on hydraulics as you don't want bits of tape in the system. NPT threads seal by deformation. That's fine for 60psi water systems but not for 2200psi hydraulics. I've had problems with them leaking. If I use Loctite 545 (tip I got here) there's no leaks. You could use 3/8 or 1/2 couplers depending on the tractor's flow.

Quick connect guide: Quick Disconnect Size Chart: DiscountHydraulicHose.com

kthompson · Mar 19, 2020

I find with fittings including couplings I am best served by removing them and taking them with me. Some part stores will carry a decent selection but tractor shop probably best option. Even Tractor Supply or such should have some options.