stjohnsmythe
Active Member
- Posts
- 474
Got the fun job of replacing my heater o rings next weekend. In doing this will I lose a lot of coolant in the cabin and will I need to top up/bleed the cooling system afterwards?
Coolant loss when replacing o rings?
- Thread starter stjohnsmythe
- Start date
This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
- Posts
- 16,482
Yes and yes....
sandyt
Well-Known Member
- Posts
- 1,615
- Location
- Wraysbury Nr Heathrow
+1 on that it can get quite messy
neo2
Active Member
- Posts
- 397
- Location
- Crook/ Durham..
ive got mine to do as well but its got bigger issues to sort first but my bigger issues were caused by heater o rings in the first place....
sandyt
Well-Known Member
- Posts
- 1,615
- Location
- Wraysbury Nr Heathrow
I am replacing a liner at present due to heating system pressurising and blowing top hose off heater rings again so because Iwaslazy its engine out again
rodntod
Active Member
- Posts
- 607
- Location
- ayrshire scotland
You could disconnect both heater hoses in the engine compartment and either using low pressure on an airline or blowing down the end of one and that will get most of the coolant out of the matrix.Gently though 
stjohnsmythe
Active Member
- Posts
- 474
Just wondering, what caused the heating system to pressurise that much?
stjohnsmythe
Active Member
- Posts
- 474
You could disconnect both heater hoses in the engine compartment and either using low pressure on an airline or blowing down the end of one and that will get most of the coolant out of the matrix.Gently though
Yes, I've seen some instructions to do just this! I can't imagine there is that much coolant in the heater matrix?
rodntod
Active Member
- Posts
- 607
- Location
- ayrshire scotland
Enough to thoroughly soak your carpets with coolant and make the rest of the job a wet and sticky hassle.Only takes 2 mins and saves loadsa mess
stjohnsmythe
Active Member
- Posts
- 474
Enough to thoroughly soak your carpets with coolant and make the rest of the job a wet and sticky hassle.Only takes 2 mins and saves loadsa mess
Once finished and everything is reconnected, is it just a case of running the engine and topping up via the expansion tank?
rodntod
Active Member
- Posts
- 607
- Location
- ayrshire scotland
just fill expansion tank,let settle then start engine and top up and burp hoses as needed
stjohnsmythe
Active Member
- Posts
- 474
just fill expansion tank,let settle then start engine and top up and burp hoses as needed
Cheers. Looks like I'm going to have a fun Saturday!
- Posts
- 16,482
I always put the front on stands when filling my V8's as this puts the expansion tank at the highest point so air will expell easier!!
sandyt
Well-Known Member
- Posts
- 1,615
- Location
- Wraysbury Nr Heathrow
Also cycle through hot to cold on the aircon system both sides as you can get an air lock in the heat exchanger
- Posts
- 16,482
Shouldn't make a difference, hot coolant always flows through the heater matrix regardless of temp position...there is no valve in the matrix.
All the temp change does is open up a flap to flow air through the matrix and mix with the cooler incoming air, when you select the temp to cold, the blend flap closes and the incoming air gets diverted away from the matrix...but the matrix will still be full of hot coolant at all times.
rodntod
Active Member
- Posts
- 607
- Location
- ayrshire scotland
sandyt
Well-Known Member
- Posts
- 1,615
- Location
- Wraysbury Nr Heathrow
That makes perfect sense I get an airlock in mine but it has been cut into to slave hot coolant for the LPG system
