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

[slavie]

In my 99 5SFE Camry with ~140k, the OEM hose (same hose but 2" longerr vs Celica) does NOT bulge like that. Your hoses are past their prime. In my experience (this was on a Mazda, btw), when the hose swells like that, the next step was that the tension clamp could not overcome the tension of the swelled hose and the system pressure, and would slowly leak at the clamp when hot.

Sure, the hose can last you another 10 years if you're lucky, or it can leave you stranded on a side of the road when it bursts.