Coolant Reservoir Tubing

[mattyd7]

Since I am replacing all the hoses in my coolant system, I thought it would be a good idea to replace the one from the radiator to the reservoir bottle since it is very hard and will probably fail at the most inconvenient time. I don't want to pull it off because I'm afraid to crack it upon removal. What are you guys using as a replacement tube? I haven't found anything on any of the usual vendors for this application. Just rubber heater hose? What internal diameter? I put the calipers on the radiator nipple and it was about 0.42", but the one on the OE reservoir is more like .50". And the tubing is quite bulged to fit on the bottle.

I am thinking best bet would be to use 7/16" ID tube and then hit the end going to the bottle with a heat gun to get it to fit. Is that what you've done?

On a side note: why are the nipples different sizes???

[TX82FIAT]

I would not worry about the bulging hose at the tank nipple. replaced mine with the standard black heater/coolant hose and it looks and operates fine.

[lglade]

I did mine recently and I think I just used some 3/8 low pressure tubing from the local auto parts store. I used a heat gun to relax the end common to the coolant bottle, since the two connections are of a significantly different diameter, and that worked just fine.

FWIW, I found that my old tube was plugged at the coolant reservoir with about three inches of 30-year old dirt/grime. The nipple on the bottle was plugged up too. So plan to take a little extra time to run a wire through the nipple and make sure it's clear. I pulled my bottle completely out and cleaned it up with a bottle brush before reinstalling it. But that's just me; I'm sure it was perfectly functional after clearing the nipple.

[RRoller123]

+1.

Just cleaned out my coolant bottle over this Winter, and it was lined with a thin black sludge-like material that I assumed was mold. The nipple was nearly clogged as well.

[mattyd7]

Thank you for the replies. I'll go with 3/8". After I was thinking about it more I figured that would be more a appropriate size for a tight seal on the radiator barb. Gates sells a hose called Radiator Overflow Tubing in 3/8" so that sounds like a good choice.

[KevAndAndi]

When I received a new coolant bottle from Autoricambi, I was puzzled at first by the accessories that came with it. There was a short length of hose that was large enough in diameter to fit on the bottle's nipple, and there was also a black plastic adapter, one end of which the short hose fit onto, and the other end of which appeared to fit the same diameter hose that would fit on the radiator nipple.

As I was using silicone hose for the main overflow hose, I also replaced the short, larger diameter hose with a silicone equivalent.

The assembled arrangement may be seen in the attached photo. (I don't know whether Autoricambi or anyone else sells just the adapters.)