I blew a transmission cooling line on the freeway a few days ago on the 89 and had to flatbed it back to the house. Last night I removed the rear rubber hoses and had planned to look for a local hose shop to rebuild them, but I can't help but wonder if these hoses could be replaced the same way many of us replace our FI hoses using high quality hose clamps, assuming the right type of hose was used.

I did some Googling and found a few "experts" that say the pressures are around 50 psi or less, and hose clamps would work fine (this was on "normal" cars)

Has anyone out there tried this, or know any reasons why it wouldn't work?

 

I would suggest to have the hoses installed with properly crimped fittings. atleast one owner did the clamp route and discovered shortly after that his screw clams were leaking thus the job had to be done over..
do it right, do it once.

Note have the hose shop install new heat sheathing to the flex portion of the lines especially over the cats

 

Don,

The ATF cooling loop operates at low pressure. As I understand it is simly a loop to circulate ATF to the cooler and back which in principal is why you cannot sue a tranny cooler as an engine oil cooler that operates at around 75 psig.

When I wanted to by-pass the radiator cooling loop I took a calculated risk and had a hydraulic line made up, properly crimped at one end, and cut the hose in the engine bay to link it to. I used a domestic brass gas pipe fitting with serrated barbs as a joining insert and locked it a jubilee clip. For sure it i no Porsche standard but I find it has worked fine for over 4 years.

As Merlin says, doubtless better to do the job correctly but if you do not have the local resources then a DIY home fix is quite feasible, if only to get you on the road until a permanent solution arrives. Just be careful with what you do in the locality of the exhaust system if you go down this route.

Fred

 

Don't use screw clamps as they will eat in to the hose, use EFI clamps like those that come in the fuel injection kits.

 

Sean,

Definately thinking about the FI type clamps, maybe even two on each connection. I did find a hose shop near by, so will probably see what they say, but if they can't rebuild them, may try the clamp route if I can find the right hose and clamps.

On an 89, there's no rubber over the cats, only towards the rear where the exhaust isn't nearly has hot, and of course up front in the engine bay.

 

I just dremmel the crimp ends and use the EFI clamps. Did it years ago on my car using ATF hose and it's been great. If the hoses and clamps can withstand 3x the PSI that will be in this system, I'm sure we will be ok.

 

I tried to remove the entire lines last night but couldn't quite get them out. I have the car on a lift, so plenty of room. With all the plastic holders off, I was able to gently bend down the line to the lower radiator enough to Dremel off the crimp fitting and install new Gates transmission line with FI type clamps. I think this will hold up fine.

The line to the upper radiator, and seperate cooler, seemed to be a different type of hose, without crimp fittings and in much better shape, so I left it alone. I replaced the rear rubber hoses with the same hose/clamps, so about ready to fill it up and get it back on the road.

Transmission fluid is everywhere. It is so strange the way it continues to seep fluid long after you think it's empty. I made the mistake of moving the catch pan after I thought the draining was complete, next morning, huge puddle on the garage floor. Then while removing the filter, which was full of fluid, it slipped out of my hand and hit the floor, splattering everywhere. Very messy job, but almost complete. (my first time).

 

Just blew a line today and was flat bedded -- will have to see what the line actually looks like.

There's a hydraulic supply house right next to the shop -- but they are historically pretty
proud of their work -- we'll see.

Mike