Otterstat install tips

[DMC-Ron]

I'm set to install a new otterstat this weekend and would certainly appreciate any tips or suggestions. Here's what I thought might be a good approach, so let me know if it seems OK or if there's a better method.

1. First jack up the rear so I have ample room.
2. Catch pan under car and several towels readily available.
3. Fill up the coolant system expansion tank and put the cap back on.
4. Get the new otterstat ready by putting on the gasket the putting a little stem lubricant around the gasket to make it easier to insert.
5. Pop off the retainer clip on the existing otterstat. (How careful do I need to be? I don't have a new replacement clip. Worst case have some plastic ties ready.)
6. Get the new otterstat at hand ready to insert.
Two choices:
7a. Rock the existing otterstat and gasket back and forth to loosen the pull both otterstat and gasket out together - immediately insert new otterstat with casket.
7b. Try to loosen the otterstat and gasket. Then pull out the otterstat followed closely by pealing out the gasket (while keeping the hole plugged with thumb) then quickly insert the new otterstat with gasket.
8. Is there any flaw in assuming I can insert the otterstat with gasket attached? Or is it necessary to get the new gasket in place then insert the new otterstat?
9. Reinstall the retainer clip.
9. Remove excess from expansion tank.

Any comments or tips would be greatly appreciated. Don't want to overthink this but would like to loose as little coolant as possible.

Thanks,
Ron

[PJ Grady Inc.]

I'm set to install a new otterstat this weekend and would certainly appreciate any tips or suggestions. Here's what I thought might be a good approach, so let me know if it seems OK or if there's a better method.

1. First jack up the rear so I have ample room.
2. Catch pan under car and several towels readily available.
3. Fill up the coolant system expansion tank and put the cap back on.
4. Get the new otterstat ready by putting on the gasket the putting a little stem lubricant around the gasket to make it easier to insert.
5. Pop off the retainer clip on the existing otterstat. (How careful do I need to be? I don't have a new replacement clip. Worst case have some plastic ties ready.)
6. Get the new otterstat at hand ready to insert.
Two choices:
7a. Rock the existing otterstat and gasket back and forth to loosen the pull both otterstat and gasket out together - immediately insert new otterstat with casket.
7b. Try to loosen the otterstat and gasket. Then pull out the otterstat followed closely by pealing out the gasket (while keeping the hole plugged with thumb) then quickly insert the new otterstat with gasket.
8. Is there any flaw in assuming I can insert the otterstat with gasket attached? Or is it necessary to get the new gasket in place then insert the new otterstat?
9. Reinstall the retainer clip.
9. Remove excess from expansion tank.

Any comments or tips would be greatly appreciated. Don't want to overthink this but would like to loose as little coolant as possible.

Thanks,
Ron
"8. Is there any flaw in assuming I can insert the otterstat with gasket attached? Or is it necessary to get the new gasket in place then insert the new otterstat?"
You must install the seal first as the otterstat expands the outer wall locking it in place and providing the pressure to seal.
Rob

[Jonathan]

Don't want to overthink this but would like to loose as little coolant as possible.

I would be more concerned with getting the new otterstat installed correctly and sealed properly than whether you lose some coolant while doing so.

Have a suitable catch container for what you spill and then have some new coolant on hand to refill what you might lose. It would be smart to bleed the system of any potential air before calling this job finished anyway. You'll introduce some air into the piping no matter how quick you think you can get the new otterstat in place.

If you're replacing the otterstat because it is defective, then doing some thorough testing of it before any extended driving is smart too. The last thing you want to deal with is thinking your new otterstat isn't working properly because it won't turn on the fans or read the higher coolant temperature yet all the while it's because you're dealing with air pockets in the system.

[David T]

If you do it quick, holding your finger over it so you don't lose much coolant, you should not get enough air in that you should have to bleed it. Also have the radiator cap on the header tank while doing it, it will help keep air out and slow down the amount of coolant coming out. DO NOT use any kind of sealer on the gasket or the switch!. Make sure the opening doesn't have any scratches or burrs that could cut the seal. Don't try to reuse the old seal. If you still have the old style pipe where the switch in on top you should modify it to the later type where the switch is on the bottom. Lubricate the seal and the switch with some coolant and install the seal first and then the switch.

[Rich]

Good inputs from all so far.

Adding more tips here, some you probably planned anyway:

- Jack it up if you like but this can be done from the top if you're the right size to grab the otterstat and twist/rock it out by reaching it from above. If you work from below then the leaks will tend to run along your arm.

- To keep mess to a minimum get an old bath towel or similar large rag. Fold it to maybe 12x 18in and arrange it just beneath the otterstat fitting after you take off the wires. The idea is to keep coolant off of everything, including the frame as well as the floor.

- With the otterstat pipe rotated up it's easier to pull the o'stat up out of the hole as well as put a thumb over the hole during the process. Slightly loosen 2 clamps, rotate pipe 180 deg so o-stat is facing up, then do the replacement. After the new o'stat is secured then flip the pipe back over, tighten its clamps. You may need extra towels to handle the clamp leaks....

And of course this all assumes you don't plan to just drain/replace the coolant. If the coolant is >18months old then do this in the middle of the coolant replacement that you should be doing every 2 yrs anyway. Which moves the mess someplace else...or gets done at a shop.

[David T]

You should be able to get 5 years out of your coolant. Test it annually for strength and PH. Keep it at 50/50 or -40 F and 7.5 PH. Changing it too often is wasteful and expensive. You can use the "good old green stuff" AKA Prestone.

[Chris 16409]

- With the otterstat pipe rotated up it's easier to pull the o'stat up out of the hole as well as put a thumb over the hole during the process. Slightly loosen 2 clamps, rotate pipe 180 deg so o-stat is facing up, then do the replacement. After the new o'stat is secured then flip the pipe back over, tighten its clamps. You may need extra towels to handle the clamp leaks.....

This is the method I've used. It works well. I think it's the best way to prevent coolant loss.