jasander77

I replaced the radiator and both fans yesterday in my '90 Accord. The whole process was fairly easy and I was very happy to find that I have no leaks. But ... it seems that I've immediately developed a transmission issue ... which leads me to believe the radiator swap is the cause. But I can't seem to figure out what's causing it.

At least a pint of transmission fluid was lost when I disconnected the AT cooling hoses ... including what was still in the radiator. After I put everything back together and refilled and tested the radiator I checked the AT fluid ... but it still showed to be full ... which surprised me.

Today I experienced some shifting issues until the transmission warmed up ... both times I drove it. The first thing I checked was the AT fluid ... and still showed to be full. I also checked the TCM for an error code ... but it didn't show an error. The TCM was also replaced recently.

My question is this ... could there be an air pocket in the transmission fluid lines causing it to read full ... when it's actually low?

Jason

19Accord97

Just drain the transmission fluid and refill it until it says full.

It will probably be close to 3 quarts since you lost more.

jasander77

Thanks ... will give it a try.

Any idea why it still shows to be full? I would have thought the remaining fluid would have been pumped through the entire system by now and would be reading a little low. Or is it a slow process? If it's a slow process is there a threat of damage due to the fluid loss?

ChevelleSSLS6

It sounds like you checked it after a brief test drive. Am I right? If your auto trans fluid is at a safe level, I'd recommend draining the fluid and refilling it. Sure they may be 'sealed' but I think it's due to too many DIY folks thinking they can check transmission fluid cold with the engine off. I'm sure you know better than that!

Also, GF's dad has an Accord similar to yours... 4cyl manual though... any tips or anything for changing out the radiator? He needs a new one... the stop-leak stuff held off the inevitable for a couple weeks, but I think the time has come. I figure if I can get him to do a 'guys afternoon project' of it or something then it'd save him a bunch of $$$$ over taking it to a shop.

jasander77

When I first experienced the issue I was the way to my in-laws. It did it again on the way back and checked it as soon as I returned home when everything was at operating temp. After a couple days I ended up draining the transmission fluid and refilling it. I continued to experience the issue after the first or second complete stop ... but never again during a trip until the car was turned off and allowed to sit a while. However ... I drove it twice today and once yesterday and it seems to have stopped for now ... fingers crossed. I'll probably end up draining the ATF fluid a couple more times in order to flush it completely.

The radiator swap was really simple ... should be the same minus the ATF cooling lines. Only took about an hour or so labor-wise. I spent longer cleaning up dirty areas since I had access. I also ended up replacing both fans since I had everything out ... you might want to keep that in mind. Wait until the car is cool ... pretty obvious though. Remove the splash shield from under the car to gain access to the bottom of the radiator. Remove the radiator cap ... remove the drain plug. Then remove the upper and lower radiator hoses ... remove the radiator brackets at the top of the radiatior ... and the two screws holding the A/C line brace that spans the radiator. You'll also need to disconnect three fan connectors. One on the radiator fan (passenger-side) and two upper and lower on the condenser fan. You will also have to remove the reservoir ... might want to clean that out while you're at it ... mine had lots of sludge at the bottom. It should then just lift out.

Transfer the lower bushings and the fans ... if you don't buy new ones ... and then reinstall everything. You should only need a single bottle of the recommended 50/50 pre-mixed coolant ... and still have a little extra ... but then again I think the M/T radiator holds more fluid than mine since you don't have the ATF cooling area. You'll need to find the air bleed bolt on the water pump ... it's on the top and has a little nozzle on it. Loosen it up a tad ... and then refill the radiator to the bottom of the filler neck. Tighten the bleed bolt 10 N-m or 7 lb-ft as soon as coolant starts to run out in a steady stream ... w/o bubbles.

This part gets kind of messy. With the radiator cap off, start the engine and let it run until warmed up ... or until the cooling fans come on at least twice. Add more coolant if necessary. Reinstall the cap, run the engine again and check for leaks. Be sure to refill the reservoir too.

Not verbatim ... but this is directly from the factory service manual.

Mine went flawless ... except for the tranny fluid. :-\

ChevelleSSLS6

sounds a lot easier than it went on my Jeep... gosh that was a pain... corroded auto tranny lines kinked and so I had to use my mcguyver skills haha to put it together. And of course the mechanical pulley mounted fan was always in the way. I'm glad Jeep is fixed!!!

I sent GF's mom a link to this, and she'll send it to GF's dad. Hopefully he'll check it out and want to tackle it with me. I think it'd be fun.

7520

I just changed out the rad on a 1992 honda accord. What brand or where did you buy the rad? I got mine at Orielly (109), honda dealer wanted (314). Couldn't afford the dealer rad.(tough economic times)

ChevelleSSLS6

I didn't buy a replacement rad yet... still waiting to hear from GF's dad on this.
He's not being a procrastinator or anything, he's at work lol.

maxman1228

I’ll just say that changing the manual radiator should be a way easier job than automatic. It’s kind of the same job. Everything minus the ATF cooling line. If the tranny is slipping, I would say adding new ATF oil. Will be bad because your transmission adapted to the shavings from old ATF oil. But I’m NO PRO but from experience. GOOD LUCK