Transmission fluid leak (Page 1/2)
Cliff Pennock JUN 30, 10:14 AM
So I finally found where my Fiero has been leaking transmission fluid. And by quite a bit I might add. Reason I never saw it before, was because I was looking in the wrong spot. Basically, this is where it's leaking transmission fluid:



(not my car, just a photo I found of the underside)

These are steel lines, right? How hard is it to replace them? Or can they be patched?
theogre JUN 30, 10:36 AM
Depending on size of hole/damage could be solder close /w metal patch or cut and splice w/ hose.
Think is plane steel not SS... If SS then normal solder types won't stick.

⚠️ Heater, Fuel and Vac Hose types often do not work. Hose Must be rated to take Hot Oil even tho these lines see Near 0 PSI for most GM auto trans.
Should be easy to find local because need this to add aftermarket trans coolers for light trucks etc.

------------------
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(Jurassic Park)

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RWDPLZ JUN 30, 10:50 AM
I've done about every repair to these cars, and THAT (replacing the transmission cooling lines) was about the biggest pain in the ass there was. When I moved back from California in 2016 the idiot that was hired to move the car ripped the lines off the car because he left the hooks on the trailer deck and they snagged the lines, which is the reason I haven't driven the car since then, I still haven't replaced them again.

Removing the front tub is a must, and dropping the front suspension out of the car to route the lines would be easier than trying to bend them around them.

Inline tube makes the lines, Fiero Store sells them if nobody in Europe has them

https://www.fierostore.com/...%20%208487&d=371&p=1
ArthurPeale JUN 30, 10:59 AM
Can you use NiCop instead of steel? The PO of my car changed it from a manual to an auto.

I don't mind the auto - for now - but I'd like to route lines from the transmission to the front radiator.

Currently, there's one of those small transmission radiators in the wheel well. It's not ideal.
css9450 JUN 30, 01:42 PM

quote
Originally posted by RWDPLZ:

Inline tube makes the lines, Fiero Store sells them if nobody in Europe has them

https://www.fierostore.com/...%20%208487&d=371&p=1



I bought a set of those but haven't gotten around to installing them, mainly because I've heard how much work is involved. They look really nice!

My car has what looks like a home-bent set of tranny cooler lines, most likely installed by Bob Stieger / Twin Lakes Fiero many years ago. They're functional, but ugly - they don't follow any of the factory bends and droop precariously in a few locations. One of these days I will replace them.
theogre JUN 30, 02:50 PM
If rest of line is good, could cut line anywhere and splice w/ hard line and compression fittings but believe this is 5/16" tube or other "weird" sizes and non-standard for plumbing even in the US so can't just go to store to get line and fittings.

This is why many patch using either method above.

Replace the whole thing need to pull spare tire well... Not hard but watch out for a front brake line attach to that or will need a brake line too.
Cliff Pennock JUL 04, 05:01 AM
With such low pressures, what would be the problem be of simply using a piece of (heat resistant) hose and two of these:

InTheLead JUL 04, 09:35 AM

quote
Originally posted by theogre:

If rest of line is good, could cut line anywhere and splice w/ hard line and compression fittings but believe this is 5/16" tube or other "weird" sizes and non-standard for plumbing even in the US so can't just go to store to get line and fittings.




Agree with Ogre, can probably order something online without much hassle but I don't think you'll find anything locally.

theogre JUL 04, 12:38 PM

quote
Originally posted by Cliff Pennock:
With such low pressures, what would be the problem be of simply using a piece of (heat resistant) hose and two of these:


The clamps won't be a problem...

Trans and Motor Oil "eats" many plastics regardless rated for "High Heat." Fuel does sim to most plastic including "fuel rated" plastic for small things like weed cutters etc. that often need fuel lines replace every few years. (Even before Gas has Ethanol..)
Wrong hose May work for a while then fail w/o reason or warning sometime later. Even low/no pressure line can empty whatever and if you're very lucky find out before does damage or cause a fire.

Many places have right hose to use for this. Even many local auto part stores because many sell aftermarket trans cooler parts. Just search transmission cooler hose. Confirm is 5/16" but can even get metric equiv for this, 8 to 9mm, as clamps doesn't care for this if size doesn't match 100%.

while there... Get 1 meter min of hose because hoses in the back likely are iffy after 30+ years and uses same size hose. May not need extra work right now but saves time to get later.
long loop on one hose is "Anti Drain" for torque convertor and need the loop. Save over wrap hose and install on new hose for anti wear/damages.
wgpierce JUL 08, 07:38 PM
You can use those clamps and trans line cooler hose, but it would be best if you could flare the ends of the line with some kind of bead flare. Without a flare the clamps will probably still leak. Hydraulic fluid is sneaky stuff If you can'd do that try double clamps on both sides at least.