02 XC70 Transmission Flush From Bottom

[zotparkerm]

I was (am) underneath the front end replacing the driver's side fog lamp and found pulling the plastic bits pretty easy.
While I wait for delivery of the fog lamp I am also doing all the brakes and planning a transmission flush.
I found (and have now lost) a thread about pulling the lower tranny line from the radiator/cooler instead of the top, but I think it was for a different year model.
Since I have all that plastic out of the way, is it easier (less messy) to pull the bottom line and slip a tube over the line than to get a tube to stick in the radiator?
If so, is there any vacuum in the system that will keep the radiator from dumping when I pull the line or should I wear goggles and a snorkel while doing so?

[ericjp]

I've always used a fiber reinforced clear hose pushed in the top port on the radiator. I think it's 5/8 inch. I have about 10 feet that I run into a container that I watch when flushing the fluid. I pump about 3 quarts out and then stop and refill. Pretty easy and only lose a few drops when pushing the transmission line back in.

[kutcht1]

You being in Texas I would cut the top hose, do the fluid transfer and add an ATX cooler to those hoses you cut. Mount that in front and keep things cool. That is exactly what I did and I am in Minnesota where we only get 10 hot days a year. Never heard of an ATX failing because it was to cold.
TomK

[Astro14]

You can pull either line. Pulling the bottom line results in spillage of about 8 oz of fluid from the trans cooler, but the hose slips over the line. That's the way that I do it...

I've added a cooler in the return line on the XC. I've added a cooler with thermostat and a spin-on filter in the return line on the T5. Time will tell if they make any difference, but the plumbing is relatively straightforward...

[Scopeman]

Astro,

What cooler and thermostat did you use?

[Astro14]

Derale 13011 Fluid Control Thermostat Kit
Derale 25750 Remote Filter Mount Kit
B&M 70264 SuperCooler Automatic Transmission Cooler

Had to use about 5 feet of hose to complete the routing. Fluid goes from Trans to radiator to return line/spliced to filter. Filter to thermostat. From thermostat to both cooler and return line into trans pan.

So, as fluid flows out, it gets warmed/cooled by coolant, then goes through filter. Above 80C, it goes to B&M cooler. Below that, the filtered fluid goes back to the transmission. I used a K&N filter, a big one, but don't remember which size. The Derale filter mount fits a wide variety of filters...

[Astro14]

7138713771397140

From left to right: the cooler mounted below the bumper, the filter, the filter with thermostat in view, and the plumbing by the radiator.

Some notes: I removed the bumper for access. I mounted the cooler in front of the condenser and intercooler to get the best/cool air. I used some aluminum bar stock, heated just enough to bend easily, that I pop-riveted into the bumper mount to mount the cooler. I did the same with the thermostat. I bolted the filter mount into the frame itself, and used a nut captured in a wrench. I slid the wrench into the frame so that the nut was on the inside, and the bolt went in from the outside. I also used lock-tite to prevent those bolts from ever loosening.

I routed the lines so that there were minimal bends. I shot every bolt with some zinc primer to prevent rust. I used stainless steel crimp (Oetiker) hose clamps - far, far faster and cheaper than worm-type screw clamps. Took 10 clamps. The routing took the hoses close to the fog lamps. The cooler, filter, lines and hardware took nearly 2 quarts of fluid to get back up to the proper level. It should be easy to remove the plastic guard under the bumper (one screw) to get at the filter and the filter was mounted so that a filter wrench would be an easy swing to get it on/off.

[sanfelice]

I love Oetiker clamps but getting the torque to squeeze them in tight locations is nigh impossible.

[Astro14]

I've since changed the transmission filter on this set up, and it was easier than the oil filter on the car. A bit of fluid dripping (horizontal mount, can't help it) but it comes off and goes on easily and the wrench fits easily with good access. I did a drain and fill of the fluid, which was perfectly red and clear. I'll do another D&F next oil change and a flush/fluid exchange in another 15,000 miles.

182,000 on the car and the original, much-maligned, 2002 AW-55 transmission shifts perfectly. The car is being driven by my 20 year old son in Virginia now, but I had it in Colorado through last winter and it shifted perfectly even in 0 degree (F) weather. The set up keeps the fluid from being too cold, as it gets warmed by the radiator, then cooled if needed via the thermostat. I really think that this is the ideal set up for both longevity and performance - but the extra expense probably keeps most manufacturers from this level of effort.

On an interesting technical note: the transmission on my new Tundra has a thermostat for the cooler line. It doesn't open until about 120F and the cooler is BIG. It's a plate type, over two feet across, ten inches high, and sits in front of the condenser. The lines appear to route directly to the cooler, no loop through the radiator (the truck only has a thousand miles on it, so I've not spent a lot of time under it, just a bit of time checking things out). To flush/exchange the fluid, or even to check the level of the fluid (there is no dipstick) requires pushing in a plunger on the transmission and pinning it in place which keeps the thermostat open so that the fluid is flowing through the cooling loop.

On a truck designed to tow (9,500# capacity, unless you're pulling the Space Shuttle for promotional reasons), Toyota has adopted a very similar setup to this one, sized up for greater capacity. I may add a spin on filter one day, but from the factory, it's a serious cooler.

It also comes with an engine oil cooler, but that's another topic...

[tosoutherncars]

From left to right: the cooler mounted below the bumper, the filter, the filter with thermostat in view, and the plumbing by the radiator. (...)

Astro, thank you SO much for posting this. I have a 90 mile 2005 XC70, and have only recently installed a hitch. Was looking for a good aftermarket cooling solution; you have clearly done this right. Very helpful, especially with parts numbers etc.

Regards,
Duncan

[billr99]

Astro, thank you SO much for posting this. I have a 90 mile 2005 XC70, and have only recently installed a hitch. Was looking for a good aftermarket cooling solution; you have clearly done this right. Very helpful, especially with parts numbers etc.

Regards,
Duncan

Duncan:

I just did Astro's setup, minus the cooler, on my R just two weeks ago. Super simple to do once you get the nose off the car. Everything is right there. Only differences on mine is that I used a filter mount where the hose connections are straight out the top rather than at right angles because I angled the filter down at about a 45 angle. I also used rivnuts (or nutserts) and M10x25 bolts to retain the filter mount to the frame rail.

I already have a Magnefine on my XC, but I think I'm going to change it over to Astro's setup next service as it makes tranny filter changes really easy and the larger filter has to be more effective. And it is pretty cheap to do as it came in at less than $100 CDN for the mount, filter, hoses and needed hardware. Well worth doing.

Cheers,

Bill

[Astro14]

Thanks guys.

An update.

The car has 191,000 on it now. It got a flush at about 188,000, along with a new filter (and a host of other work) and is now in the gentle hands of my oldest daughter in Saint Louis. She's a med student, and needs a car for her rotations.

Trans still works perfectly. The car was a pleasure to drive out there in January of this year. If looked after properly, the Volvo P2, including the "weak" transmission, is a good, durable car.

[Astro14]

Well, 2 1/2 years later - the V70T5 soldiers on in Salt Lake City. It has over 210,000 miles on it now.

It leads an active life: commuting to the hospital, driving to various sights around the city, heading up to the mountains for skiing and hiking.

It still shifts perfectly, in cold and hot weather, in hard use and in city traffic.

All good.

[NTXC]

Well, 2 1/2 years later - the V70T5 soldiers on in Salt Lake City. It has over 210,000 miles on it now.

It leads an active life: commuting to the hospital, driving to various sights around the city, heading up to the mountains for skiing and hiking.

It still shifts perfectly, in cold and hot weather, in hard use and in city traffic.

All good.

Glad to hear it, I took your direction to do the same job when I replaced my radiator. Thanks again.

[AutosDirectFlorida]

If I may, I have a question about the flush procedure.

I've done this 3 times on my 03 - first two times were by removing the top line and sending it to a jug - fill - repeat.

The 3rd time, I drained the pan - filled - went through the gears with engine running - drained the pan - filled - repeat until I put 12 quarts through.

The obvious question now is why bother with the cooler line to get the fluid out?
If I'm starting the car, running through the gears then draining, whats the difference?
Both processes cycle the fluid through the system - correct?

Considering the issues you typically have and I had prior to flushing and now its been almost a year and no issues, seems doing it this way worked fine.

Thoughts? Comments? Thanks........

[Astro14]

The multiple drain and fills mix the fluid, then you drain out a mix. Eventually, you can get close to fresh fluid, but it will take more fluid than a cooler line flush and you'll never get to 100% clean. Each time you mix it, then drain about 40% (3.5 quart drain of an 8.0 quart internal capacity). If you take a container, and remove a mix, then add 40% clean, then repeat, even after 4 times through, you're near 85% fresh, but will never get to 100%.

When you do the cooler line flush, the pump is sucking up 100% clean fluid from the pan, and forcing it through all the internal parts. When you get clean fluid coming out of the cooler line, it's 100% clean throughout the transmission, since you've been putting 100% clean fluid into the pan.