Honda/k series coolant system part 2 ie. it's still leaking!

[Dipper]

Well the new res cap stopped the odd 'one minute it's empty, next minute it's full ' carry on in the head tank and all was good for a few days. However it's back to loosing coolant. It did loose a bit over those first few days but I suspected it was air locks being cleared after replacing the pressure cap but it's loosing too much now to be that.

Engine oil is perfect and still a golden colour. Temps are spot on. It's still running the original k series rad as far as I can tell and I know the Honda coolant system runs at a higher pressure so my first thought is the rad has gone.

So what's the next plan of attack? Ive been using the car a fair bit recently so although I have seen water on the garage floor it could be coming from anywhere due to being run in monsoon conditions! Is there any non invasive way to pressure test the system without taking the clam off?

I also notice that I only have one rad fan but like I said, coolant temps have never been an issue

Cheers

[KingK_series]

Well the new res cap stopped the odd 'one minute it's empty, next minute it's full ' carry on in the head tank and all was good for a few days. However it's back to loosing coolant. It did loose a bit over those first few days but I suspected it was air locks being cleared after replacing the pressure cap but it's loosing too much now to be that.

Engine oil is perfect and still a golden colour. Temps are spot on. It's still running the original k series rad as far as I can tell and I know the Honda coolant system runs at a higher pressure so my first thought is the rad has gone.

So what's the next plan of attack? Ive been using the car a fair bit recently so although I have seen water on the garage floor it could be coming from anywhere due to being run in monsoon conditions! Is there any non invasive way to pressure test the system without taking the clam off?

I also notice that I only have one rad fan but like I said, coolant temps have never been an issue

Cheers

The honda water pump is very similar to a stock K series, a cheap pressed open back impeller running on 1;1 speed with the crank, it will run very much the same water pressure as a stock K series, possibly slightly less since the are of the impeller blades is conceivably smaller, I have a honda pump here and posted pics of both Rover and honda on the K series and honda threads. Anyway do not expect the pump causing leakage problems because you have a honda in your car.


In my experience the oem rads are hopeless and are usually dribbling coolant before leaks become noticeable, I'd change it for a all ally rad regardless and would encourage everyone to do so.


Having the coolant rise and fall significantly in the header is almost always a sign of air trapped in the system, and it is almost impossible not to trap air by simply gravity feeding the system. The OEM rad will always trap air in the end tanks because they are so badly designed, and I suspect that is the cause of significant recurrent failures with Ks that have had their head off for what ever reason. I always have the front clam off in an engine install, not just to replace the rad but utilise 2 bleeds on the top of the end tanks on my rads which is the only safe way in my mind of avoiding trapping lots of air in the end tanks.


Might I suggest a new rad, a careful fill and then see how you go?

[Dipper]

Sounds like a plan. Do the after market rads have bleed points also? Should I replace the missing fan while I'm at it? It doesn't appear to be an issue so far

Oh and standard alloy rad or triple pass?

Cheers

[KingK_series]

Sounds like a plan. Do the after market rads have bleed points also? Should I replace the missing fan while I'm at it? It doesn't appear to be an issue so far

Oh and standard alloy rad or triple pass?

Cheers

None of the aftermarket rads that I have seen have bleeds - I have mine especially made for my engines by Docking, replacing fans is no bad idea, everything fails eventually, but unless it doesn't work it is an extra expense now - it's easy to test just put the battery across it at the fan block connector.

I always have triple pass made and let the stat do the work.

[Dipper]

It's not so much that it doesn't work, it's not there at all. There is only one fan for some reason!

With no bleed points, how the hell can you get a proper bleed?

[KingK_series]

It's not so much that it doesn't work, it's not there at all. There is only one fan for some reason!

With no bleed points, how the hell can you get a proper bleed?

S1s have just one fan, it should be enough especially with a bigger rad.

how do you bleed this -



- with extreme difficulty, and I am amazed there has not been more discussion on the forums. At the factory, and no doubt a few have access to a vacuum fill.

see a u2u for someone who might mod a off the shelf ally rad for you.

[steviej]

My S2 developed a leak at the front n/s which I suspected was the rad, however it turned out to be the bleed screw in the hose, the threaded insert had started to part from the rubber, worth checking if it still has std rad and hoses fitted.

[tut]

Does the S2 have have the bleed screw on the pipe at the front left the same as the S1?

tut

[KingK_series]

Does the S2 have have the bleed screw on the pipe at the front left the same as the S1?

tut

yes they do but they are totally useless because both the bleed and the takeoff from the rad are lower than the top of the end cap - see pic.

only a bleed on the endcap will effectively bleed the rad, otherwise any non vacuum fill will leave large air pockets at both ends of the rad and probably through the rad element which is pretty useless -


here's a KingK rad, which I have specially made for my installs

[robin]

It is possible by tenacity to bleed a lot of the air out of the rad. You need to raise the front left wheel such that if you put a spirit level across the rad left is higher than the right and the front is higher (or at least more-or-less level) with the back.

Each time you do this you'll shuffle some of the air out of the system - may take repeated attempts - best solution is to work out which parking place/kerb/driveway/whatever gives you the magic inclination and then bleed radiator daily/weekly until you don't get any air out from one bleed to the next. Factory advice is to use small amount of pressure to assist in the bleeding but that's obviously tricky if you don't have a pressure source that can be used (it's not a lot of pressure - don't go hooking up an air compressor!).

An easy bleed with a tyre that's had a lot of the air removed from it could work (obviously with coolant rather than brake fluid in it).

You'll never get all the air out, but you get enough out for the system to work - after that, who cares?

Cheers,
Robin

[woody]

An easy bleed with a tyre that's had a lot of the air removed from it could work (obviously with coolant rather than brake fluid in it).

That's the method I've always used, manual suggests 5psi. Have never filled the container with coolant, but rather made sure the header tank was completely full before starting; saves cross contaminating the easi-bleed.

A good thick pair of gloves is reccomended for bleeding the front plug as well. I reconfirmed to myself yesterday that coolant at 90ish deg is a bit ho to the touch.

[Dipper]

Cheers
Looks like a fun weekend taking the clam off then!