After radiator change - problem and questions

[Bossworld]

Changed out what looked to be an existing Coolparts radiator for a replacement while the car was in bits.

Having done lots of reading, swapped the top drain for the one off the old rad (and looks like this had been done before).

Also wrapped both that and the lower drain point threads with a healthy amount of PTFE tape.

Problem 1: I'm getting a drop from the upper vent outlet, despite the thumbscrew itself seemingly being water right. See pic - I've had to leave the hose on to stop the drip


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Question: it's getting late so only had about 10 mins to idle the car and see if it was Ok. The temp only went up a couple of bars, and I was getting lukewarm air from the vents. Do I just need to go for a proper drive or does it still sound like it could be an airlock?

I've done all the pipe massaging and squeezing to get air out of both vent points (prior to idling the engine).

Thanks

[Bossworld]

Sorry to answer my own post but:

1) Overnight, the coolant that had formed in the drain tube, has gone.  Suspect it's gone back into the rad after several hours.  With a bit of searching on here, Patrick has previously advised to change the O-ring on the drain plug.  No idea why it was OK on coolparts rad v1. but I've ordered an o-ring pack from Maplin and will sub it out.  Don't know the structure of the rad but I'm hoping that'll put an end to it.

2) Wouldn't mind a proper answer but once this o-ring is sorted I'm going to bleed again just to be sure.

[shnazzle]

Sorry to answer my own post but:

1) Overnight, the coolant that had formed in the drain tube, has gone.  Suspect it's gone back into the rad after several hours.  With a bit of searching on here, Patrick has previously advised to change the O-ring on the drain plug.  No idea why it was OK on coolparts rad v1. but I've ordered an o-ring pack from Maplin and will sub it out.  Don't know the structure of the rad but I'm hoping that'll put an end to it.

2) Wouldn't mind a proper answer but once this o-ring is sorted I'm going to bleed again just to be sure.

It's a funny thing, that o-ring. It fits tight but it never seemed to seal. The Halfords one I replaced it with was ever so slightly thicker but immediately stopped any dripping.
I've been in touch with CoolParts (Advanced Radiators in Newcastle) and they said they'd look into it but it would help if I had sizes. I didn't take note of exactly which o-ring I used so I can't measure without undoing my plug and losing coolant
So, if you do figure out which one it is exactly, keep one aside and send it to Advanced Radiators. Then perhaps they can supply them with those going forward

[Joesson]

At the opposite end of the radiator to the bleed valve outlet pipe spigot there is another similar spigot. That is from where, last year I lost all of my very expensive Toyota Long Life coolant from.
I cured that leak by fitting a length of blanked off hose to that spigot, but would be interested to know what is ( was in my case) sealing that spigot when new.


As for your refill I suggest you keep some coolant with you for topping up and check the level frequently until you are sure there are no air locks to which our 2's seem prone when refilling the coolant.

[Bossworld]

Thanks Patrick and will do. It looks like the Maplin kit is the same as Halfords but a third of the price. The 'o ring' fitted to the stock plug on the new radiator looks like jagged plastic, let alone being made of rubber.

Joesson - I've seen that other drain point mentioned but neither this Coolparts one I've just fitted, nor the one I took off, have it. I've wrapped PTFE around the lower point and cross fingers that one is OK. Not sure how much I'll lose taking the top vent out to swap the o ring but planning on temporarily putting the screw type one back in to stem the flow.

[gazza1286]

I had the same problem with a leak on my old mk2 drain and bleed valves. My box of o-rings didn't include one which was just the right size. Decided to get one from the dealer (£2.90 I recall). Obviously it worked perfectly. These seals have so many options and as they deform over time it's difficult to compare old with new. £2.90 is very expensive for what it is,  but worth it for peace of mind.

[Bossworld]

Ok, so a bit of time last night, and not really a conclusive answer.

The great unknown is whether the Toyota drain valve (butterfly?) that was fitted to my previous Coolparts had the O-ring changed. I suspect not, but it looks to me like it was a 7 x 2 o-ring. This is too narrow for the gap on the valve.

I tried a 6 x 3 but it barely inserted, and got torn up while screwing in.  A 6 x 2.5 (in the Maplin kit, and in Patrick's) seems to fit better, and that is the only one of the smaller sizes bigger in width than 2.

In the end, I pulled the o-ring that came with the valve on the new Coolparts rad, and surprisingly, it is a silicon o-ring but it is already slightly deformed. I wonder if they have already fixed this previous 'known issue' as it's clearly oversized.  The inner hole is much smaller than the 6 x 2.5 in the kit, but the OD is about on par with a 6.

Either way, I've re-used this o-ring on my Toyota valve and it seems to have completely stopped the leak.

So in brief, it appears that A. Try the Coolparts ring on the Toyota valve first, and B. failing that, try a 6 x 2.5 o-ring.

Also, left the car idling after bleeding it again, and it settled down very happily and the vents were putting out hot air. So it looks like I'm golden 

Car seemed to settle at 1100rpm. I still have about 1cm of free play in the accelerator so I don't think I've done anything when cleaning the TB.  The ECU has been reset (and I'll disconnect the battery again) but frankly, after three months, the car just probably wants a few good drives.

Will try and get some o-ring comparison photos up later.

[Bossworld]

Had to remove the Coolparts o-ring from the Toyota screw and revert to a 6 x 2.5.  It was causing a leak through the thread.

Right, hopefully I can remember what these show.

1) Outer diameter of the Coolparts top bleed screw (9mm) - obviously the o-ring sits in a slight recess, so without callipers, it's either a 6 or 7mm o-ring required.
2) This is the badly squashed, oversized o-ring supplied with the Coolparts rad.  ID approx 5mm, width is something between 2.5m and 3mm but difficult to tell with it being squashed.
3) O-ring as originally fitted to the Coolparts top bleed screw (you can see how badly distorted it is).
4) Coolparts top bleed screw, with the o-ring borrowed from the Toyota valve - too narrow.
5) Coolparts top bleed screw with a 6 x 3 - this proved too thick.

6) Toyota bleed screw with plenty of PTFE tape and the original ring.  Believe this to be about 7 x 2.  Too thin.
7) Difficult to make out, but that's a 6 x 2.5 sat on the top of the Coolparts o-ring. You can see it's oversized and or deformed.
Toyota bleed screw, with a 6 x 3, after removing from the radiator. You can see it's too thick and has deformed.


tl;dr - the 6 x 2.5 seems the best match in the least scientific way possible.

[Carolyn]

An old thread, but it's nice to keep the info in one place.

I replaced my radiator a few months ago.  After a few hundred miles, I noticed that the expansion bottle was nearly full.  I re-bled the system and it settled back down.

After another 150 miles or so it's on the rise again.

I can only think that air is getting sucked in, in small amounts, whenever the system cools.  I don't have a coolant leak, but, then, coolant is a lot thicker than air.

I shall change the O ring and check the hose connections.

[Carolyn]

The O rings arrived from Sealforce this morning.  Fantastic service, as usual.  £2.56 for ten incl postage.

I now recall that I had been 'clever' and I'd swapped the O ring of the coolparts bung onto my old one.  Mistake.

The new O ring is indeed marginally fatter than the Coolparts one.

Air now removed from the top of the rad and bottle level back to 'normal' (whatever that is).

[Bossworld]

The O rings arrived from Sealforce this morning.  Fantastic service, as usual.  £2.56 for ten incl postage.

I now recall that I had been 'clever' and I'd swapped the O ring of the coolparts bung onto my old one.  Mistake.

The new O ring is indeed marginally fatter than the Coolparts one.

Air now removed from the top of the rad and bottle level back to 'normal' (whatever that is).

What size did you go for Carolyn?

[Carolyn]

The O rings arrived from Sealforce this morning.  Fantastic service, as usual.  £2.56 for ten incl postage.

I now recall that I had been 'clever' and I'd swapped the O ring of the coolparts bung onto my old one.  Mistake.

The new O ring is indeed marginally fatter than the Coolparts one.

Air now removed from the top of the rad and bottle level back to 'normal' (whatever that is).

As you advised, and as I measured and compared, I went for 6mm ID with a 2.5mm wall.

What size did you go for Carolyn?