Transmission Cooling Hoses / SS Line Questions

[jtehfreaks]

Hello all, the rubber section of the transmission cooling lines for my automatic '87 are starting to leak. The hoses currently installed were put in by the previous owner, and with them being in the shape they are, I figured that I might as well build some SS braided lines to replace the currently installed hoses.

Does anyone have a pic of the engine bay for an automatic 944, especially around the water pump/power steering area so I can get an idea of the proper hose routing? The drawing in the PET (309-10 for reference) make them look pretty straightforward, but some photographic confirmation would be nice. The current hoses take a trip around the PS reservoir, so I'd like to get the new hoses situated properly.

Also, does anyone know the length and size of those rubber hoses? The ones currently installed are 3/8" hose at about 2.5' a piece. I'm confident 3/8" hose will work just fine, as it has for 8 years now, and it's mostly the length I'm concerned about, especially when you consider the significant length savings by not routing anything around the PS reservoir.

Regarding the fittings that go into the radiator; for the upper hose, does anyone happen to know, or know where I could find, the thread size/diameter for the connector piece (part 9 in the PET) so I could get the properly sized female connector to screw onto it? The PET's description simply says "ALL 10", which is mysterious, to say the least. The lower hose uses a banjo fitting; would anyone have a clue as to what "A 8" means in the PET description, that might get me to a properly sized banjo fitting for the replacement hose.

Finally, does anyone have any tips or resources worth looking into when it comes to building SS hoses? I'm going to go with the Magna-Clamp style hose clamps to attach the hoses to the hard lines running above the headers, but I'm also wondering if I should go with a compression fitting instead.

I know this was a lot of text, so if you made it this far, thanks for reading, and thanks for any information you all might be able to provide. When I start getting things together, I'll be sure to post a follow-up in this thread. The pic below is the current state of my hoses.

[BoxsterGT]

I can help w Metric Hoses & Fittings.

You do NOT need to go through the expense of Aeroquip lines when it appears these fittings are Low-Pressure.

The common Fuel & Oil Hose for Porsche are 7.5mm ID and 9.5mm ID. If the ones on there now are 3/8 then the original was most likely 7.5mm.

To fit the Metric threads you will have to buy adapters to Aeroquip and are going to a lot of expense for such a simple task to repair.

The corresponding thread size for a 7.5mm Hose is M14x1.25.....


Len dot Cummings at verizon dot net

[jtehfreaks]

Sorry to resurrect such an old thread, but I finally got to moving on to this project and installing it on the car. I went with some -6AN lines and some Earl's fittings; the hardest part to source ended up being the compression fittings, and Lindsey Racing was the only place I could find with the 10mm to -6AN fitting required to mate the hoses to the tubes. In case anyone else wants to tackle this, here is a list of the parts I used, along with links. I could make these for other people, if they're interested, but my schedule is crazy, and it would definitely be a made-to-order type of thing.

Most parts were bought from ANPlumbing.com, such as:
4 Straight swivel seals - Earl’s AT800106ERL
4 gold replacement seal sockets - Earl's 898063GERL
1 AN to metric adapter - Earl’s AT9919DFHERL - For attaching the lower tube's hose to the upper radiator port

Pelican Parts:
1 washer for above fitting - 900-123-007-30-M131

JEGS:
1 Banjo bolt and fitting - Vibrant Performance 11524 - Comes with both washers! Used to attach the upper tube's hose to the lower radiator port.

Lindsey Racing:
2 10mm to -6AN compression fittings - I'd love to find a different source for these

I bought my stainless steel hose from ANPlumbing.com, since they also sell pre-cut lengths of hose in addition to the fittings. It was pretty convenient, though the hose ends were frayed and needed to be re-cut a bit (the zip-tie method is best method, by the way). I got a 1 foot and a 2 foot section of hose, though as you can see from my pic, I'll be removing a few inches from the 2 foot section. Installation is simple on the radiator end; just thread the fittings into the ports like you would the original hoses. Installing the tube side required cutting the tubes to fit the compression fitting over the flared ends of the tubes, which turned out to be easier than the fuel lines, due to there being some more room to work with. All in all, this cost me about $200, which is a ton compared to the rubber lines I used (but they started to leak within a few months), but it's still cheaper than the $400ish it would cost to buy the OEM tubes with the rubber hoses installed on them... not to mention the headache of working at the back of the engine to remove and replace the original lines. Also, I like how they look in the engine bay; they add a bit of bling like the fuel hoses.

[agraz220]

What fitting did you use for the a/t return on the radiator?

Just bought a 1984 944 that didn't have a radiator, so trying to track down the fitting the non banjo hose goes on. Even just the thread size into the radiator would be perfect.

Thank you!

[BoxsterGT]

They are M14 x 1.5 thread size & pitch.

The fitting PN is N 900 450 1 and uses a M14 crush ring washer.

The Banjo is a 14mm and also uses (2) of the same crush ring washer.

I hope this helps.

Len

[River77]

Originally Posted by jtehfreaks

Sorry to resurrect such an old thread, but I finally got to moving on to this project and installing it on the car. I went with some -6AN lines and some Earl's fittings; the hardest part to source ended up being the compression fittings, and Lindsey Racing was the only place I could find with the 10mm to -6AN fitting required to mate the hoses to the tubes. In case anyone else wants to tackle this, here is a list of the parts I used, along with links. I could make these for other people, if they're interested, but my schedule is crazy, and it would definitely be a made-to-order type of thing.

Most parts were bought from ANPlumbing.com, such as:
4 Straight swivel seals - Earl’s AT800106ERL
4 gold replacement seal sockets - Earl's 898063GERL
1 AN to metric adapter - Earl’s AT9919DFHERL - For attaching the lower tube's hose to the upper radiator port

Pelican Parts:
1 washer for above fitting - 900-123-007-30-M131

JEGS:
1 Banjo bolt and fitting - Vibrant Performance 11524 - Comes with both washers! Used to attach the upper tube's hose to the lower radiator port.

Lindsey Racing:
2 10mm to -6AN compression fittings - I'd love to find a different source for these

I bought my stainless steel hose from ANPlumbing.com, since they also sell pre-cut lengths of hose in addition to the fittings. It was pretty convenient, though the hose ends were frayed and needed to be re-cut a bit (the zip-tie method is best method, by the way). I got a 1 foot and a 2 foot section of hose, though as you can see from my pic, I'll be removing a few inches from the 2 foot section. Installation is simple on the radiator end; just thread the fittings into the ports like you would the original hoses. Installing the tube side required cutting the tubes to fit the compression fitting over the flared ends of the tubes, which turned out to be easier than the fuel lines, due to there being some more room to work with. All in all, this cost me about $200, which is a ton compared to the rubber lines I used (but they started to leak within a few months), but it's still cheaper than the $400ish it would cost to buy the OEM tubes with the rubber hoses installed on them... not to mention the headache of working at the back of the engine to remove and replace the original lines. Also, I like how they look in the engine bay; they add a bit of bling like the fuel hoses.

hey man, do you have more pics of this? I've been thinking about this for years and just stumbled on this post.

I think mine is leaking in both spots and had the idea to go stainless so it stops dripping over the exhaust

[Monkey Wrench]

I've never actually seen a stainless steel hose. I have seen rubber or plastic hoses with a braided sheath. it protects against abraision but what are the chances it will ever wear through? You might like the cosmetic appeal. I do not think every "stainless" hose is of equal quality in it's construction.

I just ordered a variety of hose sizes from a local supplier thinking I'll change any that fit as I get into things. they aren't metric but I had the option of buying marine rated fuel hose which is quite thick and fuel rated. whether it will fit anywhere, Jury's out on that.

[BoxsterGT]

A brief comment on SS Hose:

The Braided SS cover on rubber hose is for abrasion protection in Aircraft & Race cars, ONLY. It does not change whether it leaks or not.

Yes, SS hose is looks impressive, but the rubber hose within still fails with age & conditions.

AND, unless you peel back the braid and read the production info you never know what you actually have......



or where it was made (China??).

Race cars get regular inspections between races, and aircraft hose is subject to replacement EVERY FIVE YEARS by regulation.

On the more common useage of Fuel systems, the higher fuel pressures of todays vehicles prevent the average owner from assembling hoses with clamps, as they will not endure the long life expected. The alternative is AN with adapters, or Crimps assembled by specialists.

Clamps are fine for low pressure applications but NOT for higher pressure systems.

Today, all vehicle manufacturers use Crimped fittings like this:





or have gone to Polyamide Tube with Insert style fittings like this:



With the values of our vehicles today, there is reason enough to not take any chances.

Len