If anyone else uses the 'light' interface (see bottom left corner of page), you'll have to highlight the post with your mouse to be able to read it. I cannot understand why the colour options for this forum's interface have certain combinations which are completely invisible (white text/white background). Just a rant and no fault of the poster.

We look forward to your photos and progress report.

TC

 

Dont use the bloody MLS gasket then!

If the liners are loose and turning by hand, you need to remove them and reseal. (not recommended)
If they are solid you can just use the standard elastomer gasket.
Unless its below the block it will work fine.

You need to scrap the head if it had liner identations before the skim right around the fire ring. If it was very very slight or just on the exhaust side you will be ok.

I have done allot of K series engine work.
Please use your common sense and derive your own conclusions from what you can see from your engine.
Not what you have read online.

Hope that helps.

 

I,ve heard quite a few different opinions on the HG type with pros and con for both.
After checking the liner height they do seem to be quite low and were lose so my plan was to use shims re-seal and reassemble with MLS HG.

 

How high are the liners above the block ? measure them with feeler gauges and a straight edge.
Once you give these measurements we will advise you further,

do not just think they are low, measure them, even when they are high, they feel low with your fingers.

 

And don't be put off by richardszt post, I've just resealed all four liners on a TF.

If i can do it on a TF, anyone can do it on a 75.

 

Its not recommended because people often cock it up and its quite a lot of work.

I give honest/realistic advice, its the only thing to do.

 

I measured the height of the liners and they were below the recommended height so I used shims to bring them up to the correct height and resealed them. Also added the up-rated oil rail and used the MLS HG.
Started up fine but still seems to be pushing combustion gas into the cooling system, can't think what to do next try a different HG??

 

Please change the colour of your text, it's a sod to read.

 

Hi there!

Have you measured the liner heights? Based on my experience, I am not convinced that the liner heigths is that critical as many claims. As long as they are flush or above the block deck, it should be sufficient as long as you use the elastomer gasket. The liners has probably been like this since the engine was new. If they are below, the engine has probably been cooked during its life... I think the condition of the cylinder head is a lot more critical issue to do a successful repair. If the cylinder head is annealed due to overheating (gone soft) or have surface porosity in the fire ring area, it will most likely fail sooner or later and is probably the most common cause for a repeated HGF. Most garages are not aware of this issue. That`s why I think fitting a head saver shim together with the elastomer gasket is an essential key to make this work.

This is what I have done several times, and have worked very well: http://www.the75andztclub.co.uk/forum/showpost.php?p=1421110&postcount=74

You basically have three ways to go, with pro`s and con`s:

1. Fit an elastomer gasket only.
+ More tolerant for uneven/low liner heights.
+ The elastomer has superb sealing effect and easily gives a 100% seal even if there are some surface voids in its sealing area.
- The gaskets fire rings will indent into the cylinder head if the cylinder head has been previously serious overheated (annealed or partly annealed) and fail.
- The fire rings will not seal properly if surface porosity is present on the cylinder head.

2. Fit a MLS gasket.
- Liner heights needs to be perfectly within spec.
- Seal surfaces needs to be 100% clean, straigth and have no surface voids to give a good seal. By my experience, this gasket often tends to weep sligthly so weekly coolant checks and top-ups are important.
+ Due to its 6th layer (0,3mm saver shim) it will seal of surface porosity, making this less critical.
+ Due to its 6th layer (0,3mm saver shim) it will prevent fire ring indentation in some degree.

3. Fit elastomer gasket together with a 0,5mm saver shim wellsealed to the cylinder head.
+ More tolerant for uneven/low liner heights.
+ The elastomer has superb sealing effect and easily gives a 100% seal even if there are some surface voids in its sealing area.
+ The saver shim and wellseal will seal of surface porosity in the cylinder head.
+ Due to the saver shims thickness, it will greatly prevent fire ring indentation. It may even make an annealed cylinder head serviceable.
+ The saver shim also compensates for overskimming of the cylinder head. Many K-cylinder heads out there are skimmed far below spec.
- Correct application of the wellseal and cleanliness is one important factor for success.

Good luck with you repair

 

Thank you for your reply,

The liner height is no longer an issue the shims worked and when I checked them they are at the correct height.

I am considering option 3 the elastomer HG and shim wellsealed to the head.
Can you recommend a good elastomer HG?
You spec a 0.5mm shim, the head has only been skimmed once would the 0.3mm shim work?

Hope this colour is easier to read Maxi_crawf

 

Thank you for your reply,

The liner height is no longer an issue the shims worked and when I checked them they are at the correct height.

I am considering option 3 the elastomer HG and shim wellsealed to the head.
Can you recommend a good elastomer HG?
You spec a 0.5mm shim, the head has only been skimmed once would the 0.3mm shim work?

The 0.3 shim will work, but this one is not available separately. I would rather go for a 0.5 shim + another skim to make space for it, if neccesary. If you take a measurement of the head height, it will give you a picture of how much space there is for a shim in there. There is a link for the required parts in my thread linked to above. You need a Payen BW 750 elastomer gasket + 0,5 shim. Alternatively, you can go for a MLS gasket as your liners are within spec but only go for PREMIUM quality like Payen`S MLS or Victor reins. DMGRS also have some of these in stock as well. Keep clear for the 20£ish MLS gaskets on the bay, they have allready caused enough trouble for me

 

Would you please explain to us how you measured the height of each liner, and the measurements you found.

 

I measured the height of the liners with a straight edge and feeler blades, note my measurements are in Metric not Imperial.

Liner 1. (pullley side) was so low that only on one point of the diagonal could my tinniest feeler blade 0.04mm get under the straight edge.

Liner 2. 0.04mm on the exhaust and 0.05mm on inlet.

Liner 3. same as liner 2

Liner 4. 0.05mm on exhaust and 0.04mm on inlet.

 

lets hope it was after, otherwise they are now WAY too high.

 

As I stated my measurements are in Metric and the Bore liner correct height from Rover is 0.09-0.11mm.

The liners are now at the correct height.

Problem is coming from the cylinder head, I am going to remove it again and have it pressure tested as I think a crack in the cyclinder head is causing the problem.

 

I'm not sure if my dropbox link is working but you would be able to see the finish is far from mirror smooth.

I was going to start removing the cylinder head tonight but was just too tired, think I'll leave it until Friday night.

A few photos of the Liner job:
https://www.dropbox.com/s/kczjsv8g93vox9j/20140527_184434.jpg

https://www.dropbox.com/s/o32ftmr9cn31yqk/20140527_204739.jpg

https://www.dropbox.com/s/qjpysxnn5v3mj8s/20140601_145649.jpg

 

I'm not sure if my dropbox link is working but you would be able to see the finish is far from mirror smooth.

I was going to start removing the cylinder head tonight but was just too tired, think I'll leave it until Friday night.

A few photos of the Liner job:
https://www.dropbox.com/s/kczjsv8g93vox9j/20140527_184434.jpg

https://www.dropbox.com/s/o32ftmr9cn31yqk/20140527_204739.jpg

https://www.dropbox.com/s/qjpysxnn5v3mj8s/20140601_145649.jpg

Your photos work fine.

The inlet manifold gasket looks rather dirty, as though it may have been leaking?

 

I personally thing that your liners are way too high.

 

Just got the cylinder head back from being pressure tested and they can find nothing wrong with it even after multiple tests.

So I'm now wondering where the air the cooling system is coming from??
New HG and head skimmed didn't do it, another new HG and the liners height brought up with shims still no joy. Head off and pressure tested.

Anyone got any ideas?

 

What are the symptoms? (in reasonable detail)

 

Engine starts fine and runs smooth when it starts to get to running temperature the radiator starts to overflow, when the bleed screw is opened a lot of air is released.
As yet I'm unable to find where the air is getting in to the system.

 

Engine starts fine and runs smooth when it starts to get to running temperature the radiator starts to overflow, when the bleed screw is opened a lot of air is released.
As yet I'm unable to find where the air is getting in to the system.

Presumably when the "radiator starts to overflow", the coolant system is under pressure (rubber pipes hard)?

Given that it is under pressure and there is no oil in the coolant (although your inlet manifold shows signs of there having been) then normally the only source of pressure is the combustion gasses leaking past the fire rings. Have you inspected the head around the fire rings for porosity using a strong magnifying glass? Since your head surface is a bit rough, it will be a lot easier to see porosity if you polish the head up a little with fairly fine wet and dry sandpaper, but make sure you use a large and perfectly flat sanding block behind the sandpaper. The seal on the fire ring is less than 1mm wide, a pore less than 1mm wide in the surface of the head can result in combustion gasses in the coolant. The more a head is skimmed, the more likely a problem from porosity is.

I notice the impression of the original SLS head gasket on the block. Are those marks indented or just surface oxidation? If your new gasket is not the same type of head gasket as the original then the seals may run across those indentations, they don't need to be very deep for an MLS not to seal. The result would normally be coolant weeping out the side of the block rather than air in the coolant though.

I'm still suspicious of your inlet manifold gasket, why is it so dirty around the intake runners but not around the coolant? It's unlikely but not impossible for pressure in the intake to be leaking into the coolant through that, although I doubt it would "runs smooth" in that case.

 

Sorry for delay between posts but I had the cylinder head pressure tested and it is fine I took your advice Windy and improved the finish on the face of the cylinder head and cleaned and checked the inlets for any signs of leaking and replaced the green sealing gasket.
I also replaced the radiator and remote thermostat.
Using a new Elastomer head gasket I wellsealed a shim to the cylinder head using Beinet1's advice and reassembled the engine again refilled the cooling system, started first turn and ran smoothly then as before just as it reaches normal temp the coolant rises up and over flows when the bled screw is opened a huge amount of air is be expelled. Tonight I disconnected the heating matrix connections and pressure tested it and it was fine.

I'm out of ideas on where the air is getting into the cooling system have I over looked something?

 

just as it reaches normal temp the coolant rises up and over flows when the bled screw is opened a huge amount of air is be expelled.

The way you have written that, it looks like you didn't have the pressure cap on? The fact that the coolant is only at 88 degrees average doesn't mean that parts of it aren't hot enough to boil. You need to have the engine off for a short while before either removing the cap or using the bleed screw.

Am I right in thinking the symptoms are exactly the same as last time?

Have you done a pressure check on the cooling system? Even if the cap is holding pressure, a hole elsewhere could allow boiling.

 

having come to this post late, i just want to add the cooling system filling procsess. you fill the coolant up with the bleed screw removed, when the coolant starts to flow you put the screw back in, then carry on filling till your expansion tank is about 1 inch from the top. then run the car at about 2k revs untill the coolant starts to rise, then you have to put the cap on and run until the fan cuts in and then cuts out. you then turn off the car and wait for half hour until cool enough to remove the cap gently. then top up expansion tank or remove till max level..... Kriss75, are you doing the filling process correctly...??

 

Yes the symptoms are the same and I can find no signs of leaks where air could be entering the system.

So far I have filled the cooljng system with the bleed screw removed when coolant streams out I replace it.
Then I start the engine with the expansion cap off and run until it reaches temp. This is the first I've heard of this procedure I will give it a try and report back

 

Yes the symptoms are the same and I can find no signs of leaks where air could be entering the system.

So far I have filled the cooljng system with the bleed screw removed when coolant streams out I replace it.
Then I start the engine with the expansion cap off and run until it reaches temp. This is the first I've heard of this procedure I will give it a try and report back

that part at least is where you are going wrong. you cant get the car up to temp with the cap off and not have water streaming out of the expansion tank. the cap has to go on as the coolant starts to rise. then get the engine up to temp. cooling fan on,wait till it goes off, and then switch engine off, allow to cool and top up or remove coolant to max mark...

 

I can say this pretty confidently.
If you can get to the point where you are getting warmth at the heaters.
And the top hose is full of water with no air pockets.
Then the system will bleed itself up with the cap on safely.

 

Latest update, I filled the expansion bottle with the bleed screw removed and waited for a good flow without air and replaced the screw then started the engine and ran until I could heat building at the top hose and replaced the expansion cap.
The fan kicked in but would not turn off and the hoses felt hard, all the signs that air was still in the system.
Switched off the engine and let it cool for 30mins.

I then made a header tank out of a 2 litre water bottle and using a rubber sealing ring fitted it to the expansion tank and tried filling again with the bleed screw removed, this seemed to remove the air from the system.
I took the car for a test drive but after a short distance the fan kicked in so I pulled in switched off the engine and oped the bleed screw and opened the top cap this released a small amount of air and the level of the coolant seemed fine so closed up and tried again.
After diving 25miles with the temperature needle staying in the middle and no fan kicking in all seems to be ok.

Had a good look around after the dive and noticed an oil leak which I traced back to a cam shaft oil seal, so was a bit disappointed to find this as the seals were replaced.

Tomorrow I'm going to replace the cam shaft oil seals and add anti freeze.
Fingers crossed it at stays working ok!!

Thanks to everyone who posted helpful tips, keep them coming.

 

once you fill the cooling system and the coolant flows nicely from the bleed screw, screw the bleed screw back in and do not undo again.. if you undo the bleed screw after it can and will interupt the bleeding of any air pockets etc.. all air pockets will make their way to the expansion tank eventually.. just make sure when checking coolant that you have let the car cool down sufficiently,,,ie, at least half to one hour...

 

I've never had any difficulty bleeding the K-Series, but a few more bleeding tips:

It should be done with the heater on hot - don't think that has been mentioned yet and I'm not sure it actually makes a difference on later cars?

Once the engine has warmed up you should take it up to 5000 - 6000 rpm for a several seconds as the coolant pump will then generate much higher pressure/flow which will help push air though the system.

Whenever you have the inlet manifold off, check that he jiggle valve ball bearing is free to move and not blocked with gunk. When it's reassembled, it should rattle when you squeeze the coolant pipes. It lets the air out into the expansion tank.

 

The leaking cam-shaft oil seal has been changed and the area carefully cleaned quite a time consuming job and annoying considering the seals were new, double checked all seals this time before reassembly.

The next job was to fill the cooling system with anti-freeze so I refitted my
header bottle and with it filled up with anti-freeze used it to force out the water from the bottom hose without getting air pockets.

Started up the engine and brought it up to temperature the hoses all felt good with the top hose hot but not hard as before, when the fan kicked in it only stayed on for a short time and switched off after this I turned off the engine and let it cool for 30mins then checked the coolant level and found it to be a little high so drained some off and went for a drive.
Car felt great from the start and did a total of 40miles with the average temp 24 degrees out side.

When I got home I let the engine cool right down and then got a torch and went around looking for any signs of leaks and the coolant was still at the same level, everything looks fine! Phew!

Gave the car a wash and polish before giving the keys back to my Dad, great to see the smile on his face.
He has taken the car for a long drive and said it ran fine.

So thanks to everyone who gave advice and tips along the way!!

 

So, after all that, what was the reason for your troubles ?

 

i get the impression the fault was merely incorrect filling of coolant, ie getting the car hot with the coolant cap off, water is bound to overflow,,