Replacing 300E coolant tank

[anthonyb]

Just discovered a crack in the horizontal seam of my coolant tank today. It hasn't gotten deep enough to start leaking yet, but I can see how it could with time. I'm planning on replacing the tank only, will it be alright to use the same hoses and the coolant sensor? I will be replacing the hose clamps.

Also, there's a braided line running from just under the tank cap to somewhere behind the engine compartment. How does this line de/attach from/to the coolant tank? Is there anything I need to be aware of before I tackle this project?

thanks!
anthony

[J.HIDALGO]

I just did mine about a month ago. I changed the antifreeze at the same time since you have to drain some coolant anyways. I don't know what year your car is but, in my car the only difficult part was the bottom of the tank which is held in place by pressure. It just needed a little "help". I also cleaned the coolant sensor, be careful of the contacts, and reused it. As far as the hoses, I checked them out and they were OK, except for one small one, which I cut about 1/2 inch of the end and replaced the hose clamps. All fine so far. You may want to replace the pressure cap/lid at the same time.
Good luck!

[dtanesq]

Anthony:

Would you please post your experience with your project, or send an email to me (in my profile) with those experiences, when you've completed replacing your coolant tank? Also, have you obtained the part? Where in this area (we're not too far apart) did you go for the part?

Thanks.

[anthonyb]

J.H.,

Thanks for the info. From what I can tell, the tank is held in place by two screws, and sits on a kind of post that's attached to the fender. I'm assuming by "help" you mean you had to really force it off? A couple other questions: did you have to replace anything when you pulled out the coolant sensor? It looks like there's a securing ring that may be difficult to get off without breaking. Also, there's a braided line right under the pressure cap; how did you get that off and back on?

dtanesq,

I just submitted a partshop request, and will most likely be ordering the part(s) from here in a week or two. I've been accumulating a list of repair projects and parts over the past month or so, and after I prioritize them in terms of urgency and cost, will finish up my "research" and start tackling them. I'd be happy to post my experiences when I'm done with them.

thanks!
anthony

[jylee]

Check out the over flow hose, it is the most over look item. If it is hard and dry, it need to be change out. The hose is from the expansion tank to the over flow bottle. You need to remove the right wheel, and the wheel well lining to remove and install the new hose.

jack

[J.HIDALGO]

Anthony, the screws are easy, the "post" attached to the fender is the problem. It has a rubber groomet that, in my case, was kind of dry. You can see it from under the fender lining. Be careful. Other than that, the rest was simple. The U ring was not bad but, I have the ring plyers? which I used to open it up. If you don't have them, buy a cheap set (less than five $5) in any autopart store. You may want to replace the rubber o ring behind the sensor.
As far as the braided hose, like Jack said, that goes to the overflow tank behind the fender on the passenger side. If you need to replace it, and want the original part, partshop may have or, if you are like me, buy the non-braided part at any autopart. I did not have to do it this time because it is fairly new. I did not have to remove the wheel, just turned the wheel all the way to the left. Remove enough of the wheel well lining to get to it (tight quarters) but doable. The hose just slips off with pressure top and bottom.
Good luck!

[anthonyb]

Thanks guys! I think I've got all the information I need to start this, now I just have to get all the tools and parts, and I'll report back when it's all done.

anthony

[anthonyb]

Finally did the job last night. It took me a couple hours to do, but overall I didn't have too many problems with it. I basically followed the procedure in the shop manual, but here are some observations I ran across:

1. Along with the tank, replace the pressure cap, overflow hose, coolant sensor O-ring, and any hoses/hose clamps that need to be changed. Except for the radiator hoses, mine were all original (and old). I didn't do the pressure cap, but I'll probably pick up a new one when I get the chance. My coolant was only a couple months old, so I reused it.

2. Removing the tank: unscrew the two bolts (one of them was a PITA to access) and pull up from the engine side. My rubber grommet was still in pretty good shape - just work it off the old tank and fit it back in the fender hole. Once you've got one end of the grommet in the hole, push the rest of it in and down and it should re-insert easily.

3. Coolant sensor: Re-used mine, after cleaning it off. I put a little silicone grease on the new o-ring, put it on the sensor, and fit the assembly into the new tank. Make sure the hinged part is on the bottom. To insert the sensor all the way, I took a wrench socket just big enough to fit around the plug and carefully put my weight on it until it seated.

4. Overflow hose: Mine was so brittle it came apart when I tried to pull it off the old tank. You'll probably want to remove the overflow tank when you're removing the hose. As mentioned previously, turn the wheel all the way to the left, then you can access the bolts for the lining. I think there are 8 of them, not all of which are easy to find. You don't have to remove the entire lining to access the overflow tank (I did, though). Three bolts/screws, then pull on the tank from the bottom mount.

5. When everything is all put back together, fill the tank slowly, it overflows fast.

have fun,
anthony