1997 854 - A very slow drip a junction coupler

Post by **xHeart** » 19 Jul 2015, 14:10

I keep the coolant reservoir filled between max and min mark. It is Zerex G-05.

Past several weeks it drops to min mark, and the "low coolant" warning lights up at the dash. This weekend was the third refill.

I have looked everywhere -- from heater core to hoses at the radiator. Today, I have a breakthrough, there is indeed white dried fluid residue over the engine mount cover surface, proximity to steering rack.

After running the engine to operating temperature, blower fan at 4 with heat knob at max. It confirmed my suspicion, not a trail, but enough drops to make the wetness visible. It stopped after dropping a cluster.

Minus Evaporator, ALL heating and cooling systems' parts were replaced in past four years -- a $1000 project -- blower fan and resistor November 2014.

The two hoses at the junction were the first items. I did not replace coupler at that time.
I will replace the coupler now.

I would replace the o'ring #7a, and gasket #8 on coolant pipe (item 7)

.

Are there others that you would recommend? Like the two o'rings at the heater core itself. Heater core is Behr, replaced two years ago with new O'rings.

Thank you.

Post by **Ozark Lee** » 19 Jul 2015, 18:42

That one is a stinker to get to. I replaced that O ring and the gasket but the engine was on the engine stand when I did it.

If the heater core isn't leaking I would leave well enough alone. I have had trouble with drips at the heater core even after replacing the O rings.

...Lee

Post by **cn90** » 19 Jul 2015, 22:09

xHeart,

I recommend that you get rid of the firewall coupler and use generic GATES heater hose.
See the DIY I did recently...

https://www.matthewsvolvosite.com/forums ... hp?t=69238

Post by **xHeart** » 03 Aug 2015, 13:40

Great alternate to not-so-quick junction coupler.

Still reviewing my options.
If I decide to replace the junction coupler, then what o-rings come with it, which ones will I need to purchase separately - for heater hose on firewall or the hard aluminum at heater core end?

Do I need all three items 41, 42, and 43?
#41 appears to be same for hard pipe at heater core, and heater hose at firewall junction.

Post by **cn90** » 04 Aug 2015, 08:51

xHeart,

Once you get rid of the coupler as I mentioned, then you will realize that the engineering aspect behind this (firewall coupling) is retarded. This O-ring, that O-ring this coupler, this quick connect all that blah blah blah.

The mod I did was very simple: all you need is Gates heater hose. I re-used all the barb fittings. No more coupler or O-rings to worry about.

mika · Post by **mika** » 04 Aug 2015, 14:01

I think number 7 and 8 are a hard line that he is wanting to address, not the heater hoses. It is tight over there, not sure how to help with that one. you will need to address it from underneath probably.

Post by **xHeart** » 04 Aug 2015, 14:02

cn90 wrote:xHeart,

Once you get rid of the coupler as I mentioned, then you will realize that the engineering aspect behind this (firewall coupling) is retarded. This O-ring, that O-ring this coupler, this quick connect all that blah blah blah.

The mod I did was very simple: all you need is Gates heater hose. I re-used all the barb fittings. No more coupler or O-rings to worry about.

It is easily doable with Gates 5/8".
Out of curiosity - was soft copper pipe your option. A one piece install from heater core with twist and turn, and then one connector at engine block? Coated copper tubing
http://www.muellerindustries.com/products/hvac-refrigeration/hvac-tube-and-pipe/hvac_copper_tube

Post by **xHeart** » 04 Aug 2015, 14:03

mika wrote:I think number 7 and 8 are a hard line that he is wanting to address, not the heater hoses. It is tight over there, not sure how to help with that one. you will need to address it from underneath probably.

Yes!
I am looking up the pipe from below. It travels in where the water pump is located. No leak there, just being preventive.

Any thoughts on gasket #8?

mika · Post by **mika** » 04 Aug 2015, 14:07

+10 internet points to first person to do heater with (that great looking) copper coated tubing and post pics.

Post by **xHeart** » 15 Aug 2015, 11:31

Few photos...

New coupler had a hairline, so asked Volvo for replacement.
The replacement has hairline too, but different location. No nail catch. Volvo parts says, it is safe to use.
Any feedback.

: New coupler with hairline - not a crack; MVS_0715.jpg (1.37 MiB) Viewed 1790 times

Pulled out the two hoses at the firewall junction, lower hose came out with broken coupler piece. The upper had a visible leak. These hoses are more than 3 years old, but look fit. Which one is inlet?

: upper connection; MVS_0716.jpg (942.93 KiB) Viewed 1790 times

: lower connection; MVS_0719.jpg (701.87 KiB) Viewed 1790 times