Disc freeze plug under the timing cover.

Doward

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Just install it so the convex side is out, and tap it in the center with a hammer to 'pin' it in place, right?

Never installed a disc plug, so I thought I'd check ;)
 

87witmoreboost

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To add to the last question, what is the conclusive way to install this disc plug? How the hell can it hold much of any pressure with so little outer surface area on the bore in the block?

And a simple freeze plug question - does the lip of the plug have to be flush with the block? What if it is recessed a bit? If hammered in too hard, would it go through to the water jacket?

I tried installing my plugs tonight and felt like I had an epic fail when the plugs on the exhaust side all recessed beyond the block surface and now I am afraid I need a new set of plugs. I was fighting the "do it in the smallest amount of hits possible" vs. "dont hit TOO hard".

Help?
 

gaboonviper85

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Jan 13, 2008
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87witmoreboost;1409331 said:
To add to the last question, what is the conclusive way to install this disc plug? How the hell can it hold much of any pressure with so little outer surface area on the bore in the block?

And a simple freeze plug question - does the lip of the plug have to be flush with the block? What if it is recessed a bit? If hammered in too hard, would it go through to the water jacket?

I tried installing my plugs tonight and felt like I had an epic fail when the plugs on the exhaust side all recessed beyond the block surface and now I am afraid I need a new set of plugs. I was fighting the "do it in the smallest amount of hits possible" vs. "dont hit TOO hard".

Help?

pics would really help...
 

lewis15498

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Sep 28, 2008
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87witmoreboost;1409331 said:
To add to the last question, what is the conclusive way to install this disc plug? How the hell can it hold much of any pressure with so little outer surface area on the bore in the block?

There really isnt a lot of pressure in the cooling system, not enough to pop a freeze plug anyway.

I reccomend using a socket of slightly smaller size to apply even pressure and tap it in very lightly.
 

jdub

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87witmoreboost;1409331 said:
To add to the last question, what is the conclusive way to install this disc plug? How the hell can it hold much of any pressure with so little outer surface area on the bore in the block?

And a simple freeze plug question - does the lip of the plug have to be flush with the block? What if it is recessed a bit? If hammered in too hard, would it go through to the water jacket?

I tried installing my plugs tonight and felt like I had an epic fail when the plugs on the exhaust side all recessed beyond the block surface and now I am afraid I need a new set of plugs. I was fighting the "do it in the smallest amount of hits possible" vs. "dont hit TOO hard".

Help?

A freeze plug is a press fit...the diameter of the plug is slightly larger than the hole in the block. The machined sealing surface in the block is recessed a bit...some more than others. If you look at the installed plug, the lip should be even with the machined surface...if the plug is intoo far, you'll see that surface. If it is not in far enough, you will feel a small screw driver catch on the lip if you pick at it.

You don't have to worry about the plug interfering with the coolant passage. You do have to worry about driving it into the block though ;)

lewis15498;1409342 said:
There really isnt a lot of pressure in the cooling system, not enough to pop a freeze plug anyway.

I reccomend using a socket of slightly smaller size to apply even pressure and tap it in very lightly.

Yeah there is, I've popped two...it's not pretty. On the 1st motor, I used Dorman plugs. Turns out they are on the English measuring system...Toyota plugs are metric and are about 5-6 thou larger in diameter. The Toyota plugs are steel and fit a lot tighter over time in a steel block.

You want to install a plug with one good whack otherwise you can pull in the sides due to the shape of the plug and where the force is applied (at the inside dome). Tapping is almost a sure fire way to make sure it won't seal on a 7M. Not a chance in hell I'd recommend tapping it in.

Or, you can use a tool like this:

Freeze plug tool.jpg


You use an air hammer and disk to drive the plug in. Force is applied to the edge of the plug, so you don't have the problem above. I also made this custom disk for the sides of the block:

Freeze Plug Disk 01.jpg


Freeze Plug Disk 02.jpg


The front passenger side plug is recessed more than the others...this disk allows me to drive the plug all the way in past the recess.
You can see what I'm talking about putting force on the edge on these pics as well.
 

87witmoreboost

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Well, I decided to not risk it and just ordered a new set of toyota plugs.

I'll make a tool like jdub and then I can not worry about getting in there too far. To confirm, the lip of the plug needs to be flush with the block? My big concern now is depth. And why the hell don't they make a seat so it cant go in too far!?
 
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lewis15498

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jdub;1409371 said:
A freeze plug is a press fit...the diameter of the plug is slightly larger than the hole in the block. The machined sealing surface in the block is recessed a bit...some more than others. If you look at the installed plug, the lip should be even with the machined surface...if the plug is intoo far, you'll see that surface. If it is not in far enough, you will feel a small screw driver catch on the lip if you pick at it.

You don't have to worry about the plug interfering with the coolant passage. You do have to worry about driving it into the block though ;)



Yeah there is, I've popped two...it's not pretty. On the 1st motor, I used Dorman plugs. Turns out they are on the English measuring system...Toyota plugs are metric and are about 5-6 thou larger in diameter. The Toyota plugs are steel and fit a lot tighter over time in a steel block.

You want to install a plug with one good whack otherwise you can pull in the sides due to the shape of the plug and where the force is applied (at the inside dome). Tapping is almost a sure fire way to make sure it won't seal on a 7M. Not a chance in hell I'd recommend tapping it in.

Or, you can use a tool like this:

Freeze plug tool.jpg


You use an air hammer and disk to drive the plug in. Force is applied to the edge of the plug, so you don't have the problem above. I also made this custom disk for the sides of the block:

Freeze Plug Disk 01.jpg


Freeze Plug Disk 02.jpg


The front passenger side plug is recessed more than the others...this disk allows me to drive the plug all the way in past the recess.
You can see what I'm talking about putting force on the edge on these pics as well.

I was thinking of that tool, but I didnt know what it was called. I'll take your word on hitting it hard vs lightly.

Question: I thought the radiator cap regulated cooling system pressure. I understand that the pump forces the coolant through and the thermostat would be a point of resistance, but how much pressure can it really create?
 

jdub

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The cap does regulate pressure....it's spec'ed at 10.7-14.9 psi. It's plenty to force out an improperly installed plug.
 

87witmoreboost

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lewis15498;1409558 said:
So only if its installed incorrectly? If you do it right can this still happen?

The water pressure in the block is 10.7-14.9 psi. So, the back side of the plug is under that pressure, with atmosphere on the other side. So, the 40mm plug has an area of about 1.947in^2. At 10.7psi, thats 20.84lbf and at 14.9psi, 29.02 lbf.

Under full pressure, there is about 30lbs pushing on that plug. Imagine hanging a 30lb weight from one of those plugs if the motor were on its side. If the plug isn't in tight - that sucker will pop out.

Comprendo?
 

jdub

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And then there's the genius that thinks running a JDM tyte high pressure cap is a good idea :nono:
 

87witmoreboost

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jdub, i need a favor.

I'm at work and can machine a tool for that today - but i dont have a freeze plug with me. Can you give me the dimensions on tool you made? I assume a 39mm smaller diameter to get in the 40mm plug, then a 41-42mm bore to catch the block, etc. What I can't gauge are the depths of each diameter. See my attached picture for A,B,C,D,E,F clarification.

VERY appreciated.

p1409600_1.jpg
 

jdub

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Sizes of the freeze plugs vary a bit...the OD of the plug I have is 40.39mm. Makes sense for a press fit in a 40mm hole. Here's the dimensions:

A = 36.8mm
B = 40.3mm
C = 45.7mm
D = 6.5mm
E = 3.4mm
F = 6.6mm

Be careful on the A dimension, you do not want it too tight. When the plug is driven in, the ID of the plug (37.2mm on this one) is collapsed...you want a bit of a loose fit to prevent the inside plug wall from doing an inside press fit on the disk. B needs to be pretty accurate to give you max area to drive the plug. The rest are not super critical for accuracy.

On the flat side of the disk I used a ball end mill to create a bowel shaped hole in the middle. This mates up to the round end air hammer attachment pictured...the length was for chassis to block clearance.

This is handy...especially for driving in a plug on a block that is sitting in the car ;)
 

87witmoreboost

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jdub;1409623 said:
A = 36.8mm
B = 40.3mm
C = 45.7mm
D = 6.5mm
E = 3.4mm
F = 6.6mm


jdub, that is very much appreciated. Thanks a ton. My toyota freeze plugs are supposed to be in tomorrow and that means this will likely go from a Wednesday night headache, right to a Friday night solution.
:bigthumb:
 

87witmoreboost

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p1409767_1.jpg


I made it from alum, which is really not ideal. It's what we had so I went with it. I made the hammer-face taller for some structure.

When i'm done with it, it's fair game for any other members that need to borrow.

Edit: Doward: Sorry about the threadjack. At least its all here in one thread for anyone doing some freeze plug research.
 
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