Guys
I already have asked the two of the best minds on the forum to help; but here for all to see is my problem, what I want to do about it, and a plea for help.
Two days ago the high pressure line on my power steering pump outlet to the rack blew out of its swaged fitting and dumped the fluid. This line is two years old and was bought new. The same line made the same manufacturere is sold by all the usual UK suppliers.



Therefore I do not want to use the same part again, so I am investiating using a more modern fitting system. I have found an adaptor for the rack end which fits the cone in the rack and on the other end has a 6AN fitting. This would enable me to use a 6 AN fitting-ended flexible hose. However I need something similar in the way of an adaptor for the pump end.
As you can see from the photo, the pump fitting tube has an anular projection, against which goes an O ring which is held onto a shoulder inside. My question is:
What thread size is the tube nut/the pump thread it goes into?

I am looking for an adaptor to AN6 from the pump, which will enable me to make up a top qulity high pressure hose using AN6 fittings, (which are right for the 3/8the ID of the pressure flexible) and go entirely flexible from pump to rack. This sort of fitting is what I have in mind:


Many thanks for any help!

 

Saginaw pumps from 1980 and up in GM applications were a metric o-ring style fitting, from memory it was 16mm. Earlier pumps were 3/8 inverted flare. You might consider contacting someone like Lee Power Steering to confirm this.
Russell Performance Power Steering Adapters - Russell Performance

 

The thread is 5/8"-16. However, I think you're making it this more complicated than it needs to be. I'd take your original fittings to a local hydraulic shop and have them makup a hose to the length you need with new hose and crimps. It looks to me that the original crimp failed, and it shouldn't have.

AN fittings are not hydraulic fittings, so I am thinking you are bodging together something that is due to fail. It also doubles the number of potential leak points. I would do it properly with processional crimped hydraulic components.

I do almost everything myself on a car, but hydraulics is one place I leave it to the professionals. I used to work in the oil industry and after and incident at one service company where a hose crimp let go (in a place that never should have had hose used there) and the whipping end of the hose cut a man in half, I have a very healthy respect for pressure and doing connections the right way.

 

Curious JagBoi64 - why would you say AN fittings aren't hydraulic fittings ?

Whilst I agree that they aren't in the really high pressure sense they were developed during WW2 to permit lines carrying liquids to be connected and disconnected ad nausiem without worrying about seals - A stands for army and N for Navy -

Not convinced by the 5/8-16 either - measured mine and it is an M16-1.5, Saginaw pumps went metric in the 80's.

 

My problem here in France is that hydraulic hose repairers do not carry SAE, imperial or AN fittings: BSP and metric only. Furthermore the fitting that failed seems to be impossible to buy, if it were available I would agree with you and have a hose made up. Ditto the fitting that screws into the rack. I can make up a rack fitting from tube and flare it; but I cannot fix it to the flexible, and there seems to be no way to do so using available fittings.
Any help you can give on this matter is greatly appreciated.
I have links to PTFE hose and AN fittings that are rated for over 2,000 PSI working, with a burst pressure of 10,000 psi, so as the P/S runs at about 1,100 psi, that would seem to be enough?

 

I wouldn't get stressed, if they weren't suitable the motor sport boys wouldn't use AN / JIC all over their fuel systems(and no you shouldn't mix the two), they're designed to seal metal to metal without relying on any form of gasket.

 

Not high enough pressure rating for typical hydraulic service, and I don't believe that the secuerement to the hose end is strong enough compared to a crimp fitting.

I took the end off a pump I have that came from a 1990 DD6 and the 16 TPI nicely fit my gauge. It may well be that the metric is very close and looks the same on the gauge. Similarly, the difference between 5/8 and 16mm is 0.005" - I put the calipers on mine and it lined up with the 5/8 mark, I didn't put a micrometer on it.

 

You already have the fittings from your car don't you? It's the fitting to hose joint that failed, not the metal part? A good shop should be able to reuse those metal parts with new hose and ferrules. The hose might be a problem if you can get metric only, although I don't know if it was actually metric or not. I looked up the local hydraulic place I use and their recommended hose for power steering has a working rating of 2600psi, burst pressure of 10,400 psi. Says it meets SAE 100R1AT service. Somewhat ironically as I'm in Canada, it says the hose is made in Italy (and in inch sizes too!).

I have a general dislike of AN fittings - big and bully for low pressure service, and not quite good enough for high pressure. Sort of neither fish nor fowl, I have always found a better solution for any fluid couplings. I'd want to closely investigate how strong the hose-fitting joint is before committing to it.

 

Hoses are imperial here, strangely enough!
That is the spec also of PTFE power steering hose and the AN fittings that must be used with it. Earls Performance, for example, as well as loads of others, sell power steering hose and AN fittings and guarantee them. If you can find a fitting that duplicates this, and another that duplicates the hose end, then that would be very useful; but I cannot. The hydraulic hose blokes say this is not reuseable, and I agree!

Unobtainable fitting?

 

Progress report:

The age of miracles is upon us! I ordered a LHD hose from Rockauto on Tuesday (48 hours ago) and it rocked up to the old farm this morning!
My idea was to join it to the remains of my failed hose using an hydraulic "field repair kit".
Correction to post 1, by the way, I fitted the failed hose new in 2021, since when the car has done 20,000km (12,500 miles).
When consulting Madame, she opined that seeing if I could somehow get it on without the cutting and shutting would be a better solution. I agreed with her, particularly as the remaining three swaged fittings on the failed item may well be no better than the one that failed, so splicing in a good new pump bit may not do me much good anyway.

The idea of making a LHD hose fit somehow, is to get the car mobile until such time as I can make up an AN fitting'd hose, which, in the absence of a high quality RHD replacement, is my preferred solution and which I am currently ordering the bits for. So what follows is something of a temporary 'bodge' though actually it seems quite a good one.

The Rockauto hose is of INCREDIBLY high quality. Far stronger than my failed item, metal tube MUCH thicker, swages FAR stronger and more effective. This ia a pic and the relevant info from Rockauto's site:
https://www.rockauto.com/en/moreinfo...uEKvnbFCTrudD5
which, incidentally, as a kind friend explained to me, confirms that the pump thread is 16mm.


So this is how I butchered up the assembly to make it fit my RHD car:

• The metal tube is quite easily bent out straight without any signs of it being stressed or fractured, this I did. In some of the photos below you can see the odd dent in the hardline, but nothing serious as far as its integrity is concerned. In diagrammatic form this is the idea (once more I am indebted to my friend Picasso for the diagram):

The following photos show the hose in reality:

The front of the car is on the right in this photo. The photo shows the hose fixing to the rack tower (the hose connectors face rearwards on RHD cars). The hose flexible is bent through 180° and goes under the rack towards the front. I have protected it with a silicone hose where it goes under the rack.


Here is the front side of the rack showing the hose going towards the front. It runs along the top of the crossmember, through the gap under the engine mount, so keeping it away from the exhaust.


Here is the hose appearing at the front of the crossmember. The hard line is secured to the oil cooler pipe and the anti-roll bar


This shows the hard line secured and running along the undertray to the LHS of the car


Another shot of the hardline running across the undertray


Here is the hardline ending and the flexible that leads to the pump fitting starting. This all fitted surprisingly well


The 90° fitting going into the pump

Now I am fully aware that cable ties are not permanent fixings, but they are surprisingly durable, the this only has to last for a few months while I organise my AN hose. The hose where it runs under the rack is lower than I would like (hence the protector), but at its lowest point is not quite as low as the chin spoiler. If this were to remain permanently, I would fab up a metal protector plate and fix it to the crossmember.

I was too tired after all this to fill the system and test the connectors each end for leaks. So I will report tomorrow on that aspect; but fingers crossed!

 

Cable ties - the 21st century temporary/permanent fix - very unorthodox but if it works then what's the problem ...

 

Jumping in here as I have learned my lessons with AN hoses the hard way and am happy to share my experience. If you use PTFE AN hose, it's rated to 2,500 psi which is around 2x what a power steering system produces. It has exactly the same number of leak points as a traditional power steering hose. Finally, when it's time to replace the hose in 10 years, you just unscrew the ends and remove/replace the hose itself.

That being said, if you use the nylon braided hose that is only rated to 350psi on your power steering system, it's going to leak. I learned that lesson the hard way

 

Test report:
Scounged some ATF and filled the system this morning. All good, and after a fast test drive absolutely no weeps from the pump or rack connections. The connections are also of a better quality on the US item and seal more reliably and easily. Were it not for the rather vulnerable under-rack path of the hose, I would happily leave it; but when funds permit, or Father Christmas comes, I am going to build a PTFE/AN hose utilising adaptor fittings on the pump and rack, so that I can make a safer OEM-type path for the hose. I will post about this, including links for all the bits needed, in case others need or want to do something similar.

I cut open the failed fitting, and found out that in fact it is not a swaged fitting at all. The fitting is more like an hydraulic 'field repair kit'; video explanation of that system here:

The outer fitting, from which the hose pulled out, is a field repair kit-type coarse threaded part. The inner steel tube is barbed (rather than threaded as in a field repair kit) but the barbs are not that deep. Looking at the piece and how it is constructed, I am pretty sure the flexible was screwed into the coarse threads and this simuktaneously pulls the barbed inner piece into the flexible as it screwed down into the outer. I do not think this is an adequately robust design for the stressed environment of the V12 XJS engine bay.

The other three fittings joining the flexibles to the hardlines on the failed hose are the same type; thus there is no proper swaged clamping on any of the four fittings on the pressure hose. I attach photos of the cut open failed piece, as well as a closeup of the US hose's proper swaged fitting, for contrast.

Barbed inner, this gets pushed/pulled into the hose. Barbs not that deep.


Cut-open outer showing the coarse thread. It is down this thread that the flexible outer is threaded into the fitting. This outer fitting cannot be swaged.


The proper swage on the US supplied LHD high pressure power steering hose that I adapted.

 

Good work adapting the LHD hose! I hadn't realized that your old RHD hose was that type of fitting I thought it was the same as the LHD hose.

As a thought, since the GM pump was used on all sorts of cars, can you find a hose on Rockauto or elsewhere that has the same fittings and the length you need for RHD? Could your local hydraulic guys could use those ends from the LHD hose to make you the hose you need?

 

Indeed; but how could those swages be re-used?

 

Apparently, the inner portion that goes into the hose is all that is needed, the outer ferrule can be replaced. I have had this done to my 1966 S Type, they reused the inner portion and made me a new hose with new ferrules crimped properly.

This forum has a thread about making the hose from the GM pump, the 90 is the part you need?
https://gbodyforum.com/threads/sagin...ittings.79967/

The 90 with M16 thread is EDELMANN 39106, available at Rockauto again.

 

Thanks very much for the link. I did not know that the clamped part was separate from the tube, so that is good info.
I am now looking for a similar part that fits the rack. I have the 5/16ths tube and the 1/2 x 20 flarenuts in stock for the rack, but I do not know if the hose repairers can somehow fit to the tube, such as fit an olive, to make a secure protrusion on the pipe for the swage to lock to.
Anyone have ideas on that, by any chance?

 

Update

Guided by Thorsen, late of this parish, and now residing in the Mark VII parish, I decided to go modern and try using AN fittings; but special ones that are the required type for PTFE high pressure hose. PTFE hose is good for about 3,000 psi, and the power steering runs at about 1,000. I found out that Evil Energy do all sorts of adaptors etc etc and Père Noel duly delivered them. These are the parts I have acquired:

Adaptor: 16mm to -6 AN. The pump high pressure outlet is 16mm O ring seal:

Adaptor: 1/2 inch UNF to -6 AN for the steering rack end:

90° PTFE fitting to turn the rack outlet across the rack to run the flexible to the LHS (remember this is a RHD car):

45° PTFE fitting from the pump, to direct the hose down to the cross member:

And the PTFE hose itself:
https://www.summitracing.com/parts/sum-220984

The adaptors have been fitted to the car, and I used Loctite 542 hydraulic sealer on the threads, in addition to the flare and O ring seals, to be belt and braces as far a sealing the adaptors to the pump and rack is concerned. I am leaving them for a day or two before starting on the flexble and the connectors. More to follow.


Pump to -6 AN adaptor

Rack to -6 AN adaptor

 

Final assembly
Yesterday I fitted the adaptors to the rack and the pump. I also fitted the flexible PTFE steel braided hose to the 90° rack end fitting, and fitted it to the rack finger tight.
Once on, I fed the hose across the rack and along the bottom of the subframe and up to the pump. I marked the hose for the correct length and removed it. With some trepidation I cut the hose and fitted the pump-end 45° fitting and offered it all up, screwed onto the adaptors each end finger tight. Length OK, all good.

I left it overnight and today nipped up the fittings tight. There was a problem at the rack end as finger tight is one thing, getting a spanner on another. The AN fittings need 3/4 inch spanners and it was impossible to tighten the rack end fitting because of all the other pipework in the way. Luckily, I had foreseen this problem and had also bought one of these, which is just over an inch long:

I screwed this onto the rack adaptor, and tightened it using a using a socket, the 90° fitting was then screwed onto the extension. This enabled the fitting to be tightened with a spanner, as it was then far enough away from the other rack pipework.

Tested and all good and bone dry. I thoroughly recommend this as a high quality alternative to poor quality aftermarket parts. Connecting the AN fittings to the hose was easy, there are loads of YouTube explanations (remember it has to be high pressure PTFE AN hose) and the whole thing cost no more than the lowest UK price for an aftermarket item, and less than many UK outlets charge.

Some photos:


Adaptor, extension, 90° fitting. Grit on the engine's sandwich plate and (below) sump is because we live down an unmadeup track!



Good closeup of the adaptor, extension and 90° fitting. Fluid on the return pipe is a drip from above when fluid dripped out of the rack



Hose runs between rack and sump



Emerges on LHS and runs along the bottom of the crossmember. Cable tied to the rack body



Tied to oil cooler pipe to keep it away from the exhaust. High temperature cable ties used



Hose runs under the engine mount bracket


and up to the pump 45° fitting and adaptor.

 

Great innovative work, Greg! Well done!

I'm still intrigued as to how the design engineers came up with some of the original designs and routes to get things to fit!

I've just had to change a rear bulb on a BMW Mini Convertible and after 2 hours of my hands getting cut trying to manipulate the bulb holder into place, I believe it is not possible, and I finally had to remove the whole light unit from the car (losing a spanner somewhere inside the body in the process!) Maybe car designers should be made to run and maintain a model they designed and then they may understand the nightmare they've created!

Paul