Rack & Pinion Fitting Question

[FrankenChevy]

I have a Fox-body Mustang R&P in my '67 Camaro (also an aftermarket subframe) and I can't quite figure out what fittings I need to fab my power steering hoses. I know that the inlet port (high pressure) is 14mm x 1.5 but it looks like the return port (low pressure) is 5/8-18. This doesn't seem right but I have a friend that had a Mustang and he said that it had metric and SAE intermixed. I can see differences from component to component but a mixture on a single component doesn't sound correct. Anyone been down this road before that may have a suggestion or remember what fittings they used?

[FrankenChevy]

I posted the same question on a Camaro site and someone on there verified that there were indeed two different fittings (SAE & metric) on the Mustang R&P. I would've never guessed such a thing but then again what do I know.

[silver69camaro]

Wait! Stop!

Make sure by the year of rack you have. Early racks use all SAE fittings, and AFIAK, later racks use all metric!

It is a common misconception that SAE racks use metric and SAE, but it's wrong. It does work, but it galls the threads. The pressure side is 9/16-18 thread, and the return thread is 5/8-18. We manufacturer our own fittings to solve this problem.

[dhutton]

OK Matt, now you've got me a little worried since this is what I received from AME when I asked:

The non-metric racks (like what you have) have a 5/8" thread on the return, and 14mm on the pressure side. Both are o-ring sealed.

I bought my fitting kit from AME last September. Would it have been correct at that time? I've seen no leaks but haven't put any miles on the car, just running in the shop.

Don

[silver69camaro]

Don, that's not a problem. The 14mm pressure fitting (which seem to be an aftermarket industry standard) rarely leaks; if yours doesn't leak, leave it alone and it will be just fine.

All of our cars use the 14mm without a problem. This can only be an issue if a person has a R&P casting with nasty threads (say, in what you'd find in a chain store rebuilt R&P), then the threads get galled.

[FrankenChevy]

Fortunately I ordered the fittings and hose but have not received them yet so no damage done...yet...other than a few more useless fittings. I'll just add them to the pile of mis-ordered fittings. So I'm pretty sure that the high pressure side is 14 X 1.5.... then what size is the low pressure? Also, I did not see an o-ring fitting (14 X 1.5 to AN-6) when I looked on summitracing.com that seemed to fit my application. What am I missing here? The search engines on some of these sites can be a little tricky so it is possible that I just overlooked a "key word" to use. BTW, I really appreciate the responses. I searched this site and others on this subject but either there wasn't much discussion on this matter or I didn't hit upon the proper key word when doing a search.

[FrankenChevy]

Dang it! Right after I quit looking for something it seems to pop up. I need to quit looking sooner so I can find it sooner. After I posted the above post I went and did another quick search on Summit's site to confirm what I justed stated and this is what I found....
http://store.summitracing.com/partde...5&autoview=sku.
Will this part (Russell #648070) do the trick for the high pressure side? I still need to know the size of the low pressure side but since I thought it was a 5/8-18 then I would guess that it is a 16mm X 1.5 fitting and the following would work
http://store.summitracing.com/egnsea...=KeywordSearch (Russell 648060).

[silver69camaro]

Nope, none of those will work. The O-ring is in the wrong location and the entire body is too long. The o-ring needs to be seated under the hex.

Here's what you need to do: Take an -06AN fitting and thread the flare side into the pressure port on the rack. If it screws in nicely, you have SAE fittings (-06AN threads happen to be 9/16-18). If not, it's metric.

[silver69camaro]

I wouldn't be surprised if we are the only ones making the correct fittings. Maximum Motorsports may also.

[FrankenChevy]

Thanks Matt. I was looking for a fitting with the o-ring under the hex but I didn't see one. I'll try what you suggested but I'm fairly sure that I have metric threads. The threaded plastic plug that came in the port on the R&P had 14X1.5 stamped on it but then again that could be incorrect so I'll check again. Is it possible to use a fitting without a o-ring and seal the interfacing threads with teflon tape or is that a no no since it is a high pressure application?

[silver69camaro]

No, teflon tape defintely will not work. Earler racks used teflon o-rings that simply placed between the fitting's bottom and the rack casting, but o-rings work much better.

One could possibly take the fittings (if your rack is metric) you found at Summit and part off a few threads on the bottom, but the hex isn't large enough to support the o-ring.

[hotrdblder]

you can buy the fitting at summit, cut the conventional o ring stem off, then go to napa and buy metric oring that fits snug below the hex at the top of the threads.

[FrankenChevy]

Something doesn't seem quite right...the fact that I have to "make" a fitting for this application leaves me a little uneasy. I can't believe that there is not an off-the-shelf fitting that will work (attention all those who are looking for a product to manufacture and sell). Before I attempt to modify this fitting, I would just try to use the following with an o-ring:
http://store.summitracing.com/partde...5&autoview=sku
I sure wish I had looked at the R&P BEFORE I installed it. Live and learn. Part of the problem is that I can't really see what I'm dealing with.... unless I grow a third eye on the end of my finger since the R&P is somewhat buried. As long as I'm wishing then I also wouldn't mind having a second elbow on my arm so that I can reach it easier.

[FrankenChevy]

I think I found what I'm looking for....
http://www.hydratechbraking.com/prod...cessories.html
Like I said before, I needed to quit looking so that I could find it.
Amazing what you can do when you don't set your mind to do it.

[silver69camaro]

Did you ever verify the threads to make sure they are metric using a -06AN fitting?

[FrankenChevy]

Not yet. I'm at work and will do so tonight when I get home. If it is a 14mm X 1.5 threaded hole then what size would the accompanying return (low pressure) port be? 16mm x 1.5?

[hotrdblder]

yes return would be 16mm
you can do the same thing i mentioned for the pressure as the return to make them into the correct type of fitting not rocket science at all.
also if you have the plastic plugs with o rings on them that came with the rack those o rings will work also

[FrankenChevy]

I used a -06AN fitting that I had and it wouldn't quite fit, so I do have metric threads. Thanks for all the input. I would've definitely cross-threaded something.
I would have to list "figuring out the hoses and fittings" (i.e. brake, steering, cooling, a/c, etc) as the most frustrating part of this build. I have a ton of fittings that I've bought that did not fit their intended component. I guess when you have Ford, Chevy, aftermarket and custom parts coming together that use a combination of metric and SAE systems then you need to expect such. I must be spoiled since all the stuff we deal with at work is military standard and there are detail drawings so you can check your interfaces. I sure wish the vendors would provide the same but I would settle for having the correct photo with the item listed on their website or catalog. There have been multiple times that I ordered a fitting based on the picture and when it came in it looked nothing like the photo. Man that bites. Sorry for the rant... I feel better now. Thanks, again!

[silver69camaro]

Good thing you checked. Just for your reference, you have a '93 and up steering rack in case if you need replacement.