# Trouble fitting a Trailer tipping pipe kit - wrong parts?



## another Tim (9 mo ago)

Just bought this kit and I am new to hydraulic fittings.

But it just doesn't seem right to me, no instructions and three dowty washers with no apparewnt use and one connection with no proper seal.

A brief outline, 1/2" BSP fittings on the pipe a 90 degree female and a straight male. The female fits to a 3/8" to 1/2" BSP adaptor with a 3/8" BSP Dowty washer to the diverter valve and a taper on the 1/2". All parts there, and correct I assume.

The trouble comes on the other end, I have a 1/2" BSP quick release coupling that has a 3/4" UNF thread and a 1/2"BSP (taper join) to 3/4"JIC adaptor. So no apparent use for the two 1/2" BSP dowty washers.

For the 3/4"JIC to 3/4"UNF (not JIC) I have a 3/4" BSP dowty washer left.

Is all I need a simple 3/4"UNF dowty washer or is the 3/4"JIC to 3/4"UNF just not the correct way to do this?

Couple of piccies to show what I mean, how do I seal the 3/4" UNC join to the quick release? Obviously not with the 3/4" BSP washer provided:


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## HarveyW (Sep 15, 2014)

Good Morning Tim, welcome to the forum.

I see "AGRILINE" on the plastic packets for the various components. I recommend that you pose your questions to them or whoever is the supplier of the kit. It might be that they are supplying different (spare) adapters to hopefully cover connection problems you may encounter with your particular installation??


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## another Tim (9 mo ago)

I have already asked them, no solution as yet. Agriline have, in my experience, been the best supplier of quality spares and I fully understand that the "kits" are sometimes bought in and not always put together by someone with practical experience before hitting the shelves. I also understand that getting used to thread sizes and different coupling systems with their seals can be a little daunting. I don't expect them to have an unlimited supply of experts available either. ;-)

I'm not here to criticize but to support the supplier and get a kit that works for everyone.

But I'm struggling myself here as I haven't dealt with hydraulic couplings either. But after reading up on this yesterday and this morning a few things seem a little clearer.

A 3/4" BSP dowty washer doesn't fit a 3/4" UNC connection, neither are 1/2" BSP dowty washers needed for the two 1/2" BSP connections as they are both taper fittings. The kit needs work.

Now I need to resolve it ASAP to test a trailer that arrives tomorrow and will hopefully be in use the day after. Now can resolve it with a simple 3/4" UNC dowty washer available on next day delivery for £1.99? Agriline don't stock these.

The problem is that the 3/4" JIC is a propriety connection so its method of sealing is redundant when connected to a UNF fitting, and the dowty washers are NOT self centering as they are with the BSP fittings they seem to be made for.

In which case the answer may be that the best solution is to fit a quick release coupling that has a 1/2" BSP thread -- there is a spare 1/2" BSP dowty washer in the kit, and will it then fit the mounting bracket... ;-)

I'm hoping somebody has a quick, "yes that's fine, done it myself", or a toothsucking, "hmmm, not so sure of that..."


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## SidecarFlip (Mar 25, 2021)

another Tim said:


> Dowty washer


What the heck is that anyway?


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## another Tim (9 mo ago)

SidecarFlip said:


> What the heck is that anyway?


My apologies if my terminology is off, as I said I'm new to hydraulic fittings. Dowty washer is what it says on both the packet and invoice. I googled and it seemed to make sense, a washer with a bonded rubber middle bit for sealing high pressure unions.

I also googled how to seal a 3/4" UNC connection for hydraulic pipes but have not found a ready answer which makes me question if it's a common or even correct solution. If I have the part there must be a way...


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## pogobill (Jan 31, 2012)

Thanks for that explanation! I didn't know what the heck that was either! LOL


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## Vigo (Oct 8, 2021)

I'm having trouble getting the big picture from your description, but in your first pic the question that comes to mind is, why are you trying to put a JIC fitting in between a male BSPP hose and a female BSPP quick disconnect that would otherwise fit together?


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## another Tim (9 mo ago)

Vigo said:


> I'm having trouble getting the big picture from your description, but in your first pic the question that comes to mind is, why are you trying to put a JIC fitting in between a male BSPP hose and a female BSPP quick disconnect that would otherwise fit together?


That's the knub of the problem. All the parts are in a kit, and the supplied quick release is on a 3/4" UNC thread which does't fit the 1/2" BSP on the hose. So provided in the kit is a 1/2" BSP to 3/4" JIC adaptor because the JIC system uses UNC threads. Trouble is that as far as I can tell (looking it up on the internet rather than any actual experience...) the quick release should be sealed to another UNC thread via an O ring and the JIC via a taper fit (not really designed for an O ring or a dowty washer). So I'm leaning towards the opinion that these two parts are just not compatible with each other. Also there is no seal for this union in the kit unless it's the 3/4" BSP dowty washer? Kinda hints at a lack of knowledge in the individual who created this kit.

I'm pretty sure now that the only real solution to this is a quick release fitting on a 1/2" BSP thread.

Sorry about the confusion at the beginning as I was trying to describe a problem as a novice looking at a jumbel of parts that came with no instruction and didn't seem to make any sense... I think I have it straight in my head now. Just waiting for Agriline to get back to me.


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## Vigo (Oct 8, 2021)

If there is something to 'receive' the tapered cone of the JIC fitting in the base of those female UNC threads, it may just work. If the threads of the JIC and the female BSP are truly the same and you have decent thread engagement (3+ full turns, maybe?) you could probably even seal those two pieces together just by putting some epoxy on the threads before assembling and letting it cure fully before pressurizing. This, assuming these parts are going in the trash if they don't work. I doubt Agriline will ask you to ship them back..


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## another Tim (9 mo ago)

Vigo said:


> If there is something to 'receive' the tapered cone of the JIC fitting in the base of those female UNC threads, it may just work.


No taper, just tightens on the faces. The UNC has a slight taper out to accept an O ring and the JIC fitting has a very small shoulder. Agriline has 1/2" BSP quick release fittings in stock, so I'm at a loss as to why the kit is supplied as it is.

I'm sure they will send the correct part, now I know what it is, and I want to be able to send the parts back if they want.

But thanks.


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## BinVa (Sep 21, 2020)

It appears the kit supplier overcomplicated things by adapting the different types of fittings. I'm sure they make it work with what is available through their suppliers. In this case they've made a 'plumber's nightmare' out of a simple service line, which could lead to several weak points in the line. Sometimes you can do it better standing in front of the parts bin and putting it together yourself... B.


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## Fedup (Feb 25, 2014)

A "quick fix" here, but if I'm getting this right, the intent is to thread a J.I.C. male end into the quick coupler? If so you can use (even though it wasn't provided) an O ring. The #8 J.I.C. thread is the same as the #8 ORB fitting the couple is apparently made for? If that's the case, it's a simple matter of slipping the #8 ORB O ring over the male threads. Something I have done often enough. If there is room for the male tapered end inside the coupler threads with no interference, I'd use that rather than the washer. It's not designed to work with the internal taper of the ORB female thread coupler, and will be a source of problems down the road.


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## another Tim (9 mo ago)

BinVa said:


> It appears the kit supplier overcomplicated things by adapting the different types of fittings.


Yes, seems so.



Fedup said:


> #8 ORB O ring


Thank you for those magic words! It's surprisingly difficult to find a part that says, "this is the bit you need". I found male to male fittings "with (O ring) seal" and saw the taper on the coupling and figured a 3/4" UNC washer wasn't really designed for it. The 3/4" BSP certainly dosen't fit!!

I'm going to hold out for a 1/2" BSP coupling as they have one in stock and would prefer the correct parts that are designed to work together from a brand new and guaranteed kit. 

It may yet evolve to include a fix with baler twine somewhere down the line, but not quite yet...


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## another Tim (9 mo ago)

Well heard back from Agriline. They said that they had exactly the same kit and it went together fine so they would send that to replace the one I had. I did ask how they were sealing the 3/4" JIC to the quick release because the same kit will have the same problem, but he said his kit was fine. Initially he said use the dowty washers. I said from the start that I didn't think you use the dowty washers, it should be an O ring yes?

The conversation got derailed because I'm trying to confirm how to seal the joint but the guy didn't really seem interested, just said he could seal it with his kit and that it had been tested on their own tractors... But how I asked, the dowty washers are both BSP, 3/4" is 26mm across and the 1/2" 21mm, a 3/4 UNC is 19mm maximum diameter across the threads, later he said about the taper on the JIC fitting and I said the quick release wasn't JIC and had no taper.

I am a little disappointed not really because nobody knew how to fit the parts together properly, but the guy wouldn't really listen to the main question, which was quite simply how do I seal the connection between the quick release and the adapter, there's nothing in the kit to do it.


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## another Tim (9 mo ago)

To be fair to Agriline, i just got off the phone with a different adviser who called me and said straight off that he'd just put the exact same kit together and could see the problem I was having. He's sending a quick release fitting with a 1/2" BSP thread.

Problem sorted.

He said the kits were outsourced and sometimes parts were substituted without their knowledge.


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