Swollen upper radiator hose., Swollen upper radiator hose. Options

[valerit1]

I have a Celica 1995 GT. My upper radiator hose is OEM Toyota part, 7 years, 80,000 miles old. My radiator cap is new, OEM Toyota, correct 88Pa. NO overheating or drive-ability problems whatsoever.

When fully warmed, my upper hose is noticeably swollen, more so at the the engine connector. (which is to be expected as there hot coolant enters the hose before it bends).
I know OEM Toyota hoses last A LONG time. I replaced previous ones after 16 years, 150,000 miles as the precaution - they looked fine. I also know they are somewhat thin and soft even when new and supposed to swell somewhat by design.

I pressure tested my cooling system - perfectly fine. I got and tested several caps - new and used, and pressure tested them according to the OEM repair manual. Strangely, several OEM Toyota
caps I got - new and correct, 88Pa (.9 bar) actually open all past 1.5bar when tested! - some way more! (I tested about 5 from different souses - all correct 88Pa). The manual says should be within 74-108Pa, discard if less - says nothing what if more - is it OK? All cause the same hose swelling.
Now - I have one worn cap, opens almost at no pressure. That one of course causes NO swelling at all. And the car runs fine with it, no overheating whatsoever - just fills and overfills the bottle after a run - to be expected with very little pressure. That is it. And no - I do not have head gasket problems (it would not matter anyway as the cap would release the gasses)

NOW MY QUESTION - HOW MUCH SWELLING of the upper radiator hose is normal, by design, to ignore and nothing to worry about? General answers online have a lot of nonsense - you have this, you have that.

From your experience - what is the normal, acceptable swelling of the upper OEM Toyota hose car fully warmed up? With a brand new (or unworn) cap?

Thanks a lot!

Larry

[Box]

That seems a little much, if it's not too expensive I'd go ahead and replace it if it were me.

This post has been edited by Box: Feb 21, 2018 - 9:41 PM

[valerit1]

That seems a little much, if it's not too expensive I'd go ahead and replace it if it were me.

There is something strange about new Toyota caps. My old worn ones have "ND"' on the left,, "0.9" (o.9 bar) on the right. I cannot find these any more.
The new ones have "D" on both wings. Even so the both have 88Pa (0.9 bar) on it - the test shows like 1,5 bar, so they are more like newer 1.1 bar (which is a new standard pressure on most cars now)
Like I said - I tested 5 of them, all with correct labels - and all with very high release pressure. Which gives?