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expansion tank

Joined
Sep 2, 2015
hey guys so I have a 1987 volvo 240 and the dang expansion tank just sucks I have replaced one already, and the new one sprunk a leek right around where the hose hooks up on the bottom so I melted the plastic together with a soldering iron. Surprise its leaking again anyone know if there away to fix this or should I just adapt a different volvo tank?
 
Why do they keep breaking? Sounds like you have something putting excessive force on it, breaking the outlet. Maybe the hood is hitting it.
 
well firstly it is a small leak just starts to drip when it gets up to temp, but I think its because the fitting on the tank is slightly bigger than the the one on the radiator so it doesn't just slide right on, that and/or it almost looks like they pressed in the fitting on the tank.
 
Is this a stock tank? Because no one else seems to have a ton of issues with a stock tank...?
 
if by stock you mean oem then no, however the stock one I had was leaking in the same place which is why I replaced it to begin with, but what seems more likely to me is if the hose has slightly different sizes on both ends because I replaced it with a random hose and it did take some persuasion to get it on.
 
Not sure where you are, but I have a spare stock tank that doesn't leak available.

Also... wouldn't the hose being tighter make it seal better?
 
I'm in NYC tomorrow I'll be in North Carolina. You would think that, but I'm thinking because I have to push so hard on the hose to get it on it might be breaking the plastic.
 
I'm in Raleigh FYI...

Send me a PM? I don't mind shipping either... prob a pain to get it onto the plane lol.
 
if by stock you mean oem then no, however the stock one I had was leaking in the same place which is why I replaced it to begin with, but what seems more likely to me is if the hose has slightly different sizes on both ends because I replaced it with a random hose and it did take some persuasion to get it on.


The stock flatish tank and the cylindrical tank both use a moulded hose.The fitting at the bottom is 3/4" or 19mm and the fitting on the radiator is 5/8" so the hose is moulded to those sizes.

The Volvo tank is the most reliable tank I know of which is why I have used them on many many other cars when I do high performance or rally engine builds..Fords, Toyota, Mitsubishi, Opels, VW (a notoriously bad tank--always break off the tank fitting) even on my Chevy 6,2 diesel van

This was confirmed as a good choice by seeing many under hood photos of rally engines in Sweden and asking guys there on buying trips..

If you're having problems it is certainly something you are doing that is drastically wrong.

Sorry
Maybe get the OEM tank and OEM hose. They seem to last forever.
 
^^ This. I have never seen a problem with the 240 tanks.

The latest version of the 7-9 tanks had problems with the lower neck snapping off when they were 15+ years old.
 
The stock flatish tank and the cylindrical tank both use a moulded hose.The fitting at the bottom is 3/4" or 19mm and the fitting on the radiator is 5/8" so the hose is moulded to those sizes.

The Volvo tank is the most reliable tank I know of which is why I have used them on many many other cars when I do high performance or rally engine builds..Fords, Toyota, Mitsubishi, Opels, VW (a notoriously bad tank--always break off the tank fitting) even on my Chevy 6,2 diesel van

This was confirmed as a good choice by seeing many under hood photos of rally engines in Sweden and asking guys there on buying trips..

If you're having problems it is certainly something you are doing that is drastically wrong.

Sorry
Maybe get the OEM tank and OEM hose. They seem to last forever.

Seems like a good plan, love how I can find the most random sizes for anything here thanks! The drastic problem is again most likely because i'm shoving a hose which is to small on the tank :oops:
 
Seems like a good plan, love how I can find the most random sizes for anything here thanks! The drastic problem is again most likely because i'm shoving a hose which is to small on the tank :oops:


probably.
I have seen the tanks kind of "fall apart" when I have been "harvesting tanks" in junk yards but that is on cars without hood which had strong sun on them in urban areas with filthy air for long time..But in Sweden in junkyards out in the countryside, even with hoods off, the tanks were fine..
Am I right in guessing you are Greek? Well there's strong sun..Are you in urban area?
 
I am Greek, but i'm living in New York City which does mean leaving your car parked in the sun all the time. on a side note my brother found a aluminum tank for a good price for an s13 that we are going to modify to fit.
 
I am Greek, but i'm living in New York City which does mean leaving your car parked in the sun all the time. on a side note my brother found a aluminum tank for a good price for an s13 that we are going to modify to fit.

I meant hood off so the plastic is exposed..UV light is hard on most plastics..

And Mmmmmm Iduno about how wise the S13 idea is.
See, the japonaise tend to have a little 8mm line in and then an overflow..pissing coolant onto the ground.
The stock way Volvo does the tank is really THE RIGHT WAY. They way it works is how serious race/rally cars do and it's really properly called a "de-gas" tank..

See..coolant cools...but a frothy mixture full of air doesn't cool in the same way (air being a nice insulator..So if you're making some heat and the coolant in direct contact with say the head around the exhaust port and it is boiling the coolant right at the surface --you get bubbles in the coolant..
The stock set up pisses that coolant into the tank and the frothy aerated coolant sits on top, and the all liquid coolant drawn off the bottom goes back to the rad either directly like stock Volvo or in some of the cars I have done, via a T in heater return pipe.

It is a VERY GOOD way to plumb the car...In my V4 powered Saab I had cooling problems and bleeding (got to bleed out the air or I would have severe cooling problems--Saab being nice, gave you a bleed screw on the back of the heater element to do this) and just replumbing the car to use the Volvo 240 tank solved all the problems..It was a "single change" experiment so the change was clearly result of the re-plumbing..This allowed me to run 1 step hotter heat range for the spark plug...and solved a tenancy to wet the plug on cold starts on cold days. I did this in 1987 and it was interesting to see that with the Saab 900 they routed the coolant the very same way as Volvo---and that was different than how they circulate the coolant in the Saab 99 with the same engine..and 900 had vastly fewer problems with localised overheating..
I believe the problem is called "nucleate boiling"..and it is a problem.

IF you decide to use the S13 tank because it's shiny mod it so it functions exactly like the OEM tank.
 
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