Transmission cooler

[thenewkid64]

I am getting ready to order a B&M stacked plate transmission cooler to add some aux cooling before I start towing my saturn.

My plan is to remove one of the side bulkheads and cut an opening in it that will accept the cooler. This should allow for good air flow over the cooler and keep the excess heat from the radaitor.

Now for the questions:

Do I bypass the factory cooler or run them in series?

If I run them in series, what line is typically the one that goes back to the transmission? I want to have the aux cooler be the last stop for the fluid before returning to the transmission.

Do I use the rubber hose with hose clamps, or go with the race style and get the threaded connectors and hoses?

Any thing I am forgetting/missing?

[87MH]

Some additional info here:
http://www.mobiletek.net/hayden.html

I would think that a good quality high temp oil quality rubber line would be ok (Hydraulic Oil Line). The circulating pressure is not very high, so you want as large a diameter as practical to minimize line loss. The radiator exchanger has a much higher thermal efficiency than an air exchanger, so leave it in line in order to cool the fluid to radiator temp prior to the air exchanger.

I would go with threaded connectors, but I know that there are clamp types in service. Certainly, there will be a lesser chance of leakage with the threaded connections. Sort of "how much is peace of mind worth?".

Give me a couple of days and I'll check which line is which on the radiator and transmission - my first opportunity to play with my new toy, a 40 to 500 degree F pistol type thermal scanner.

[74Argosy24MH]

If it is anything close to mine you will have to mount it on the right. You need to build some baffles and stops to keep the air flowing through the cooler. There is a lot of open space above, behind the headlights, and below. Air is going to take the path of least resistance. Look at what will be behind the cooler, it will impede air flow.

I would also seriously consider adding a fan. Anywhere out of the grill opening cuts air flow dramatically even with good baffling. The highest temps are going to be uphill pulls, usually these are at slower speeds (even less air). You can use a sender or switch to turn it on.

Use the radiator cooler. The coolant is hot but will still remove heat (liquid is better than air for heat exchange). The cooler will remove more. On the trans fluid comes out the upper line, lower is return.

Let the fittings on the cooler determine the hookup. I have used short pieces of hose and clamps for years and the only problem was deterioration of the rubber. Unless you are near a really decent supplier there are so many thread and compression schemes it quickly becomes a nightmare (and overkill) trying to build lines. They are also easier to replace down the line.

John

[john hd]

brett,

once you determine what line is what, you can use heavy duty brake line from napa.

the last time i installed one i just cut off the stock fitting with a tubing cutter and used compression fittings (brass).

the cooler end was threaded for n.p.t. just found the right size compression fitting for those also. male pipe thread to compression. you might find those with a 90 degree bend to help route it.

tip: save the end you cut off with about 4 inches of tubing attached. you can reinstall this piece in the radiator and use a compression fitting on it too.

a trip to a well stocked napa store should have every thing you need to plumb it.

john

ps, one of those spring tubing benders help avoid kinking your new lines.

[swebster]

Brett,
Mine uses HD brake line coming from the trans into the radiator cooler then switches to clamped high temp hose going into and out of the auz cooler then back to brake line into the trans.

I replaced te hose and double clamped everything but I still I don't really like having the clamps in there. They seem tight but there is really not positive connection being made...just a compressed friction fit which is a little scary.

I had those blasted oil line coolers made up at a commercial truck radiator/AC shop for 50 bucks. If I get the chance I plan to replace those clamped hoses on the raditator cooler with a similar screw on type.

[thenewkid64]

John, (74Argosy24MH)

I looked behind the baffle plate on the pass side and there is plenty of room for air flow into the wheel well. I remember on my 76 it was very cluttered there.
If I use the "race" cooler form B&M it comes with the threaded fittings. The normal one uses the hose clamps.

John HD,

What does a spring tubing bender cost?

I am leaning the hard line way since the lines are new to the radiator and I want to maintain the system integrity. The thought of loosing a line and having my trans fluid pour out is something I think it would be wise to avoid

[john hd]

brett,

a couple of bucks tops for a spring bender.

look in the tubing section at a hardware store. it is just what the name implies, just a section of spring slightly flaired on one end. about a foot long.

you slip it over the tubing, make your bend and slip it off. the spring wound around the tubing prevents kinking.

john

[59toaster]

I run Hayden Stack plate coolers in all my trucks. Very simular to the B&M but they come as a kit with everything you need to hook it up. The B&M you get just the cooler then you need to get the hardware to hook it up. Most people go with the "AN" fittings like aircraft would use. The hayden uses High pressure hose that is compatiable with the ATF. Never had a problem. I have run this set up for 5 years on one truck. I do keep an eye out for hose problems and I will probably replace the hoses in the next couple of years. I purchaced the kit at Pep Boys.

I also run a Hayden temp gage in my transmission pan (and my engine oil pan). My feeling is I want to see the temp AFTER it has gone through the the workings of the transmission. Heat is caused by slipping clutches. Seeing the temp after the cooler is nice if you have a pree cooled temp and a after cooled temp to see what sort of drop you get but the most imprtant thing to see is how hot that fluid is AFTER it has run theough the transmission.

On my suburban (TH400) the average temp I have seen is 180. That was actully sitting in traffic with a high idle problem (Vacume leak) so the transmission was fighting the brakes I managed to see 200 on the gage a couple times. Now that I have my idle issue fixed. Running down the road it runs about 160. THat's with the AUX cooler directly in front of the radiator.

As for plumbing it. Keep the factory cooler in line. Transmissions can be over cooled. You want them to run 160-180 range. This helps lengthen the life of the fluid. Those temps are highenough that any water from condinsations will become vapor and be purged from the transmission. Very important for that to happen.


Hayden s lititure that comes with their coolers claims dmage begins at 200degrees. Those temps start hardening the seals. They rate the transmission at about 50K if it runs 225f. at 300f they rate the transmission life in hours!


Running through the factory cooler actully helps to get the transmission up to operating temp faster. In the winter here in Atlanta when it get's to the low 30's I have to cover half my grill with cardboard to get the transmission to even register on the gage.

[thenewkid64]

The trans cooler is installed. I still need to hook up the lines, but the major disassembly fabrication and reassembly is done. I laso cut in a cool air intake for the air cleaner and routed a duct to it.

Can you see it? I know the picture is not too good.

Picture

[74Argosy24MH]

I can see it, nice job. That must have been fun to get at. Was your grille 2 piece or did you make it 2 piece?

John

[thenewkid64]

Thanks,

Grill is 2 peice..... Actually it is 3 peices. Top, bottom and the bars. 6 screws and the the bars come out. The plate was held on with 2 self tapping screws. Took it out and used a jigsaw with a metal blade to cut it. On reinstall I added a brace back to a floor strut for aditional strength. It is not going anywhere and only the top 1/2 inch has anything behind it.

[Rick Alston]

I think the transmission cooler is the best investment one can make to prolong the life of the transmission.

I am also a firm believer in synthetic transmission fluid because it is very tolerent of high temperatures. Since it is temperature that is the enemy transmission fluid because it degrades the fluid and causes poor cooling, a synthetic will last longer and cool more effectively over time.

I purchase the fluid at AutoZone for about $4.50 per quart and use about 3 quarts per filling. That's only an extra $10.50 spread over the entire year. A great investment!

[ALANSD]

so did you drain all the fluid before going to synth or add it in to the dino atf?

[Rick Alston]

I did the next best thing, which was to change out the pan fluid and filter and run the vehicle for a week to mix the non-synthetic with the synthetic to about 50-50. Then, changed out fluid only to bring mix to about 75-25. After a couple of years, the fluid must be 100%.

Incidentally, the transmission has 194k miles and still going strong after 12 years of towing 6000# of aluminum! It will get a nice (but not needed) rest with the 20 footer I just bought as a down-size move.