SAE 8 orange boss leaks

   #1  

Bsavulis

Member
Joined
Dec 21, 2016
Messages
39
Location
Putnam, Connecticut
Tractor
Kioti CK25
I have a diverted valve with 6 oring boss fittings. The orings fail frequently. I am not sure if it is poor installation or bad sealing surfaces, or something else. The oring will be pushed out in a small area around the fitting. When I install new orings I put them as tight as possible but they still eventually leak. The valve just has a flat surface for sealing. There is no counter bore. Should I try a copper ring instead? The valve and fittings are a chore to access so I would like to solve this. The orings hold for a while but then start to drip. Not all at the same time. Just one or two. System pressure is set for 2200psi.

Thanks
Brian
 
   #2  

K5lwq

Veteran Member
Joined
Aug 6, 2017
Messages
2,312
Location
Mineola, TX
Tractor
Kioti LK2554, Branson 4815C, Satoh Beaver, Speedex
You may be over tightening them. ORB normally does not take much to get a good seal.
 
   #3  

LD1

Super Star Member
Joined
Apr 30, 2008
Messages
19,452
Location
Central Ohio
Tractor
Kubota MX5100
ORB should have a small counterbore for the oring to seat into. It's very subtle....but I bet it's there. Almost looks just like using a countersink to knock the edge off the hole.

Is this ALL of the fittings on the valve that are causing issues....or just one? Maybe if just one.....the bore has a burr or something cutting the o-rings.

Also....ORB o-rings are different than your standard o-rings. So are you just finding something that looks like it will work out if a generic oring kit? Or are you actually getting ORB o-rings? They are slightly different sizes....and a bit harder durometer.

Pictures would be worth 1000 words here
 
   #4  

Zebrafive

Super Member
Joined
Aug 5, 2010
Messages
5,376
Location
South West MI
Tractor
John Deere 2030, John Deere 6415
It could be any of the above posted answers.
I am think:
You are tightening too tight, for -8 or 1/2" the torque is 34lb ft.
Wrong O-ring
Poor machining of the part the fitting mounts to.
In that order.
 
Last edited:
   #5  

oldnslo

Elite Member
Joined
Jan 20, 2010
Messages
4,932
Location
Northern, IL
Tractor
Branson 2400H, JD X540
From your description it sounds like you have BSPP ports which require a seal ring. BSPP seal on the surface while SAE have a chamfer the O-ring fits into
 
   #6  

LD1

Super Star Member
Joined
Apr 30, 2008
Messages
19,452
Location
Central Ohio
Tractor
Kubota MX5100
From your description it sounds like you have BSPP ports which require a seal ring. BSPP seal on the surface while SAE have a chamfer the O-ring fits into
I didn't think BSPP threads were the same as SAE. But I don't deal with BSPP at all. Maybe just close enought to think they are right?
 
   #7  

ptsg

Elite Member
Joined
Apr 3, 2013
Messages
3,322
Location
Portugal
Tractor
2017 Branson F36Rn (3515R)
BSPP adjustable swivel fittings will have an O-ring which can easily be confused with an ORF fitting.

My experience with Korean manufacturers is that they do use BSPP fittings on their tractors.

The idea of these fittings is to thread the fitting as much as possible without bottoming it out on the nut and till it points the right direction. The just tighten the nut. No need to go crazy on the torque either.

Here is a picture of one of these fittings for reference:

1-1/16-12 Male JIC x 1/2-14 Male BSPP Swivel Adjustable 1-1/16-12 Male JIC  x 1/2-14 Male BSPP Swivel Adjustable Inc. Brennan Industries  7202-12-08-NWO-FG Forged Steel 90 Degree Elbow Conversion Adapter Fitting  Tube Fittings Fittings
 
   #8  

oldnslo

Elite Member
Joined
Jan 20, 2010
Messages
4,932
Location
Northern, IL
Tractor
Branson 2400H, JD X540
LD1
I would have to dig out my thread chart to confirm but I think a couple of the BSPP are close enough that SAE will fit I believe biggest difference is 1 threads per inch difference same as I have seen NPT screwed into SAE ports.
 
   #9  

TractorGuy

Elite Member
Joined
Sep 15, 2013
Messages
4,287
Location
N. FL
Tractor
John Deere 4310 CUT, Ford New Holland 575E Industrial Backhoe, John Deere F725 Front Mount Mower
I'm betting you have the wrong o-rings. Go to your local hydraulic shop and get the right ones or order from one of the online suppliers. My diverter also has the #8 SAE ports and I haven't had a single o-ring fail.
 
   #10  

07keo02

Bronze Member
Joined
May 4, 2017
Messages
65
Location
Salem, Mo
Tractor
MF GC1705
If the o-ring is squeezing out and showing then either:

1: There is no counter-bore and in this case the port is not ORB.

2: There is insufficient shoulder on the fitting. This could happen in a swivel 90 where the nut/washer was removed and the o-ring was installed against the hex portion of the fitting. Same thing happens when using a Jic fitting in an ORB port without an o-ring backing washer.

3: Wrong o-rings.

Otherwise, the o-rings should not show once the fitting is seated.
 
 
Top