1996 850 Wagon NA Heater Hose Leak

banjoman · Post by **banjoman** » 25 Feb 2015, 14:19

223,000 miles. Replaced all coolant hoses, thermostat, sensors, and heater core. The new heater hoses and O-ring kit are Volvo from FCP. Put new coolant in reservoir and have major leaks from both ports in the coupler on the engine side and a small leak on the other side in the cabin. I followed the sequencing for the O-rings and spacer and made sure to remove the old spacers and O-rings; I understand the difference in the old coupler and the new. The new hoses and couplers went into the ports and clicked closed. I was careful throughout and did not notice any damage. I have seen the other posts about bypassing the current setup but want to avoid that.

Post by **dosbricks** » 25 Feb 2015, 18:03

We have the same mileage on our S70 and I went through this ritual a few months ago--minus the leaks. It sounds like you were careful and informed on how to change out the o-rings/spacers. The only thing I can think of offhand is a cracked coupler (the black plastic housing everything inserts into). Did you also replace this? Sometimes they're brittle with age and crack when manipulated.

banjoman · Post by **banjoman** » 25 Feb 2015, 18:11

I did not change the coupler. I tried to be gentle with it and did not notice any cracks but there could certainly be one given that it is almost 20 years old.

Post by **dosbricks** » 25 Feb 2015, 18:34

Probably the culprit since there is some leakage on both sides.

Post by **precopster** » 28 Feb 2015, 10:25

I always replace the coupler; they don't like being disturbed at all and will leak.

banjoman · Post by **banjoman** » 28 Feb 2015, 12:06

I have ordered one and will hopefully install it Monday.

banjoman · Post by **banjoman** » 06 Mar 2015, 14:20

To close the loop, the leak was caused by a bad coupler. A few comments most of which are explained better elsewhere . . . If you are replacing the heater hoses, install a new coupler; the one I got from FCP includes the O-rings, spacers, and yellow snap-on devices, so do not buy those separately. The coupler must be removed from the inside. Remove the accelerator by prying the pin on the left side about a quarter of an inch; the accel then slides toward you easily. Remove the upper and side screws on the heater core box and tilt it to improve access to the coupler. The old coupler seemed difficult to remove first, but then I realized that it was being held on by the thick foam insulation; go ahead and pull on it hard enough to get it out. When you install the new coupler, attach the metal pipes first; put some Vaseline on the O-rings and spacers so they slide in more easily. At first it seemed as though they would not go in, but keep at it and they will.