87 5ktq upper rad hose ID

[Doyt W. Echelberger]

The upper radiator hose failed and dumped coolant at the upper edge of the 
clamp, on the end that connects with the head. The hose was about 13 years 
old and looked very good on the outside. The inside lining had become 
spongy and resembled 1/8 inch thick black gunk.

To make a temporary repair with generic FLAPS parts (while waiting on the 
dealer to get another hose) I needed to know the inside diameter  of both 
ends.  No one on the list replied with that value. So, I have assumed no 
one knew it. This post will document the answer that resulted from 
measuring the inside diameter of the old hose when I took it off this morning.

The upper radiator hose coolant outlet pipe on the head measured 1.25 
inches outside diameter at the ridge on top of the outlet. The old hose had 
stretched beyond that dimension and was more than  1.25 and less than 1.5 
inches inside diameter, both at at the head and at the upper plastic 
radiator connection. You might want to carry a spare piece of such hose, 
and a connector pipe and some clamps and a sharp knife.

To effect the temporary repair, I cut off the hose at the failure point 
above the clamp, and discarded the one inch section containing the failure 
where it had been held by the clamp.  I could have just pushed the 
remaining hose down onto the nipple in the head and re-applied the clamp, 
but that put some tension on the hose between the head and the 
radiator.  The radiator has a historically fragile plastic nipple that 
might break off from any tension, so I tried to find a way to reduce that 
tension. Any engine movement might have increased that tension.

I bought a 1.5 inch OD straight plastic hose connector pipe at my FLAPS and 
cut the remaining upper rad hose about half way between the "T" and the 
head nipple. This preserved the existing bend in the hose near the head. I 
inserted and clamped the connector pipe  between the cut ends and got about 
an inch extra length at that point. This extra length was enough to 
eliminate the tension in the hose.

So there you have it. The repair looks good for about another 6 months or a 
year, maybe. But I have a new molded hose on order.  Other owners might 
benefit from replacing that very complex and expensive molded upper hose 
before it fails, especially if it is about 13 years old. The dealer needs a 
few days to get another one for you if the failure happens on some cold 
winter night and dumps all your coolant. Might be a good candidate for 
planned maintenance. Wish I had been that smart. But the outside of that 
hose looked so good........

Doyt Echelberger
87 5ktq