Temporary repair for a cracked radiator top tank

As Thorin has posted an excellent radiator replacement thread, which I'll be following in a couple of days, I thought I'd post up my temporary fix for the cracked radiator upper tank problem that seems to affect all stock Toyota rads at some point.

Tools you'll need:

2mm Drill bit & drill

Stanley knife

Screwdriver (small thin flat bladed)

Bucket or syringe

Solvent and a clean rag

180 Grit sandpaper

A pack of JB weld

This is the crack that you normally see weeping coolant & bubbles out of:

Copyright Thorin and blatently stolen without his permission

Step 1:

Let the engine cool down until its safe to remove the rad cap. Even though there's a hole in the rad it may still have pressure in it. Wait until the bubbles and hissing stop at the very least and USE A CLOTH OVER THE RAD CAP.

Step 2:

Check the coolant level. If its bone dry in the rad then you may have also overheated it. Can you remember what the temperature guage was at when you stopped the engine?

If its still running ok and there's no mayonaise on the underside of the rad cap and in the radiator then you're probably ok.

Step 3:

Drain the coolant down to below the level of the crack. This is to stop the coolant getting into the glue. If the rad is bone dry move to Step 4.

Either drain some coolant from the bottom of the rad drain cock (into a bucket), or use a syringe to suck it out of the top.

The syringe is best as there's a bit of dead volume around the top of the tubes and the syringe can suck all of this out. If you're feeling particularly clinical about it, stuff some rag down the cap hole with the screwdriver (keeping one end of it out to pull it back out again) and dry the inside of the top tank around the area of the crack.

Step 4:

Take the drill with the 2mm drill bit and locate the very ends of the crack. Drill into the top tank so the cracks are on the inside of the holes (i.e. just overlap the end of the crack with the hole so that the hole is slightly further out than the crack). This stops the crack going any further across the rad.

Step 5:

Take the stanley knife and use the point to cut into the crack to make it deeper. Then use the blade on its side to scratch a V groove into the crack. Make it just deep enough so that the tip of the blade just starts to break through into the inside of the tank.

Step 6:

Use the sandpaper to sand about 1/2 an inch around each side of the crack and 1/2 an inch beyond the drilled holes. Make it as rough as you can. Then take the stanley knife and scratch it up some more. The rougher the better as this is the keyed surface for the glue to hold on to.

Step 7:

Clean the area with the solvent and the rag to remove all traces of antifreeze.

Step 8:

Mix up equal amounts of the JB Weld on a piece of cardboard with the screwdriver. About 1/2 an inch from each tube is sufficient.

Use the screwdriver and dollop this into the crack. Work it in well so some goes through to the inside. Use the rest to build up the area around the crack to about 4mm proud of the surface, tapering off towards the edges.

Stick what you can (little fingers if you have long small ones) in through the cap neck and smooth the glue around on the inside), then smooth the outside off with a wet finger. Stick some selotape over it to make it smooth if you like.

Step 9:

Wait 24 hours before filling with coolant and testing.

I've done this a couple of days ago and its holding out perfectly. I even gave it full beans to get it hot & pressurised & still no leaks.

Should work as a temporary fix while you wait for a new rad if the Supe is your daily transport.

I'll post a pic of the finished article when I can get the camera to work

This is the crack that you normally see weeping coolant & bubbles out of:

[qimg]http://www.kulthea.net/fluidyne/fitting/crack.jpg[/qimg]

Copyright Thorin and blatently stolen without his permission

I considered changing the image to one of a different crack

We don't want to see your crack mate

:rlol:

I wish I had this advice around when mine went - I ended up using a metal epoxy used for plumbing - worked ok for about 120 miles, no where near as elegant as this solution though

Wot, no Duck tape?

Seriously, I've even seen chewing gum filling a rad crack, and doing a pretty good job, too

bit better than my attempt - i just used araldite... lasted 3 months

The post is now restricted to 2000 characters, so had to post this pic here.

It can be painted, of course.

Just tried this and it didn't last more than a minute! HAHA. I couldn't find JB Weld so I used some stuff from halfords that is apparently like chemical metal and can take up to 100C and high pressue! I might try and sand it down again and add some more. It did say all it needs is an hour but I might leave it for longer next time.

Use JB Weld and leave it for 24 hours mate JB Weld has:

Tensile Strength: 3960 psi

Adhesion: 1800 psi

Flex Strength: 7320 psi

Tensile Lap Shear: 1040 psi

Shrinkage: 0.0%

Resistant to: 500° F (~300°C)

The stuff you used is probably as good as bluetack

I'll send you some if you want? Or buy it here http://www.helibits.co.uk/enter.html?target=p_888.html&lang=en-gb

£7.27 delivered

Whoa that stuff does look good, I have just bought a RAD so hopefully no need for it...If I can't fit the Rad myself I will buy some of this to patch it up for the journey to the garage.

Thanks

Update - The patch lasted 3 months, the same as Hecklers.

I'm now looking at modifying my original repair by pop riveting a sheet of steel, using the drilled holes at the end of the crack, to the cracked area while also bonding it on at the same time. Then covering the lot with JB Weld, specialist plastic glue or maybe fibreglass?? Or carbon fibre for that bling look?

In the interests of not throwing out a (mostly) good rad (Scottish ancestry) for the sake of a small and very common failure of a plastic part, I'm determined to get to the bottom of this and find a permenant repair!!

The parts catalogue lists the radiator in sections, perhaps you could buy just the top section ?

See attached pic:

The parts catalogue lists the radiator in sections, perhaps you could buy just the top section ?

May try that with one of out local rad speciaists if I can't get a fix sorted, but I thought there was a problem with crimping the top tank on??? IIRC its virtually impossible to do without the special tool that does it evenly.

Has anyone got a scarp rad with a crack in it like this that I can experiment with????

Has anyone got a scarp rad with a crack in it like this that I can experiment with????

My old one is still in the garage I think, you're welcome to come collect

Update

To make this fix permanant is simple. When the JB Weld is set key it and a large area around it with coarse sandpaper & slap lots of Isopon P40 fibreglass over the whole lot about 1/2 inch thick

The JB Weld sticks well to the plastic top tank but is brittle so eventually cracks again if not supported. The P40 is very strong and supports the repair well, but doesn't stick to the plastic well. The combination of the two holds out well & should be permanant.

Smiffad has my old rad repaired like this and hopefully will advise how its holding out.

Any chance of a pic of the repair Adam??

Update

 

To make this fix permanant is simple. When the JB Weld is set key it and a large area around it with coarse sandpaper & slap lots of Isopon P40 fibreglass over the whole lot anout 1/2 inch thick

 

The JB Weld sticks well to the plastic top tank but is brittle so eventually cracks again if not supported. The P40 is very strong and supports the repair well, but doesn't stick to the plastic well. The combination of the two holds out well & should be permanant.

 

Smiffad has my old rad repaired like this and hopefully will advise how its holding out.

 

Any chance of a pic of the repair Adam??

I shall pop out and get one at lunch

Piccies added

Bump, piccys added

You could have sanded it

-Ian