MTZ Tractor Talk

Main MTZ Talk => MTZ Tractors - Old Models (Belarus) => Topic started by: Jeff in ND on August 11, 2015, 02:01:36 PM

Title: 1989 562 head gasket....
Post by: Jeff in ND on August 11, 2015, 02:01:36 PM
Hello,

There is a 1989 562 on the farm bought new by my late father.  Sometime in the mid 90s the head gasket failed and he & his neighbor replaced it.  I am not sure if the head bolts ever were re-torqued after it was run some.  For the last 15yrs or so, this tractor has not been used much, and now has about 2000 hrs on it.  Mostly used to mow ditches and blow snow.  Late last summer, after mowing, the head gasket began to fail again.  It is blowing compression out of the left side (side where injectors are) and makes a chuffing sound when idling.  Air bubbles appear along the seam of block/head.  No coolant in the oil so far I could tell.  This definitely needs repair again.

What possible extra damage may have occurred from running this a few hours after it started to fail?  Any chance the head or block are eaten away?  Why did this fail for a 2nd time?  I am wondering if the head or block are warped?

thanks.
Title: Re: 1989 562 head gasket....
Post by: imperial1960 on August 13, 2015, 02:37:29 PM
Standard to replace head bolts at H/G change.Check break away tork on head-bolts.When removing cyl head be careful and look at the H/G to see if you can see where the blow out is.Check for cracks on the H/G where it seals on the liner.Low counter bores can be cause of H/G failure too a dial indicator should be checked around the top of the liner flange easy to do.Did you ever have an overheat?Check water pump pressure also before you blow it apart.Possable head damage (cracks) or grommet damage.List goes on!
Title: Re: 1989 562 head gasket....
Post by: Jeff in ND on August 13, 2015, 09:35:12 PM
thanks for replying.

I don't think its ever been hot but no way to know for sure at this time.   My father tended to have a pretty lite foot on stuff so I doubt he really overloaded it ever.

 These are not torque to yield bolts are they?  I am familiar with those from doing heads on some 80s car engines.

I doubt new head bolts were used the last time it was apart in the 90s.  I am not familiar with liner type blocks as the only engines I have ever worked on personally are gas engines w/o wet liners.  Are you saying the liner could be pushed down too far into the block and leave a sunken "rim" around the top surface where the gasket sets?  I do know the last time this was apart, those teflon rings were installed on the replacement gasket.

I doubt I will get time to take this apart until next year.  I don't live nearby and my vacation time is up for the time being.  I am sort of afraid to take it apart as at least now it runs and could be moved but if I take it apart its dead in the shed until whenever.

Title: Re: 1989 562 head gasket....
Post by: imperial1960 on August 16, 2015, 01:54:23 PM
Removable liners have a flange around top of liner that fits inside the top of the block this is zero deck. The liners move and frett eats away the block. Then you have to cut counter bores then shim to zero deck. When the liner moves down head gasket will lose its clamping seal. I doubt your tractor has low counter bores sounds like grommets damage or lose headbolts when you start building pressure inside radiator then I would worry
Title: Re: 1989 562 head gasket....
Post by: Jeff in ND on May 31, 2016, 07:51:00 PM
I am back again after nearly a year!!

This past holiday weekend I had time to pull the head off the Belarus 562.

Here are pictures:

A left side view of the engine showing the area I had seen bubbles forming while it was running.

(http://i156.photobucket.com/albums/t5/ee-engineer/Belarus%20HG/Area%20of%20blowout%20S_zpsu6vao4f5.jpg) (http://s156.photobucket.com/user/ee-engineer/media/Belarus%20HG/Area%20of%20blowout%20S_zpsu6vao4f5.jpg.html)

This one shows the gasket setting on the top of the block with the head removed.  This is the rear most cylinder.  The teflon ring is eaten away.

(http://i156.photobucket.com/albums/t5/ee-engineer/Belarus%20HG/Rear%20Cylinder%20gasket%20S_zpsh6c8sumh.jpg) (http://s156.photobucket.com/user/ee-engineer/media/Belarus%20HG/Rear%20Cylinder%20gasket%20S_zpsh6c8sumh.jpg.html)

The center 2 cylinders.

(http://i156.photobucket.com/albums/t5/ee-engineer/Belarus%20HG/Center%20Cylinder%20gasket%20S_zpsdcvgtb0m.jpg) (http://s156.photobucket.com/user/ee-engineer/media/Belarus%20HG/Center%20Cylinder%20gasket%20S_zpsdcvgtb0m.jpg.html)

The front cylinder.

(http://i156.photobucket.com/albums/t5/ee-engineer/Belarus%20HG/Front%20Cylinder%20gasket%20S_zpsgweg3wg1.jpg) (http://s156.photobucket.com/user/ee-engineer/media/Belarus%20HG/Front%20Cylinder%20gasket%20S_zpsgweg3wg1.jpg.html)

The gasket as a whole.  It seems all 4 cylinders are showing damage in the same area that coincides to the side of the head where the fuel injectors are located.  Is there a reason for this?

(http://i156.photobucket.com/albums/t5/ee-engineer/Belarus%20HG/Whole%20gasket%20with%20damages%20S_zpscpxijsgd.jpg) (http://s156.photobucket.com/user/ee-engineer/media/Belarus%20HG/Whole%20gasket%20with%20damages%20S_zpscpxijsgd.jpg.html)

The tractor is 3-1/2hrs from here but I took the cylinder head back with me to have it checked for flatness.  I will be looking at the liners being even/level when I get back to looking at this later this summer.

Unfortunately for me, this tractor is not close by and the location is pretty primitive with lack of space and dark with a dirt floor.  I had to take extra time to dismantle the steering shaft to get it out of the way of my crane to pull off the head as I was working alone and this head is too heavy for me to lift easily.

Any comments appreciated!



Title: Re: 1989 562 head gasket....
Post by: Haymaker on June 01, 2016, 10:24:57 AM
Yes make sure the head is straight and not cracked.  But as for the plastic Teflon rings ... not sure what the theory is behind those as really what are they gonna do??  ITs the steel compression ring in the head gasket that does the sealing of combustion.  When I did mine I got the head gasket from MTZ and there was no Teflon rings nor did mine have them when I took it apart.  The new one was a well made head gasket like you'd get for you're typical diesel engine. Maybe years ago they used a different style.

Make sure you clean those cylinders out and oil them if you're going to be leaving it sit for a long time.  All the threads in the head and have to be cleaned out and inspected.  The head bolts can be reused but again all wire brushed and cleaned off good. Also as mentioned below check that liner protrusion.  Wouldn't be a bad idea to get a bolt and washer to clamp down those liners encase they want to lift up while turning the engine over by hand with the head off when you're cleaning stuff.

Belarus states in the service manual that head should be retorqued  again after like 50- 100hrs. 
Title: Re: 1989 562 head gasket....
Post by: imperial1960 on June 02, 2016, 03:24:52 PM
If it is Teflon could be why your H/G failed call MTZ see if Teflon seals come with the H/G set.Maybe teflon seal was a shipping item to protect the liner surface.Let us know what you find!
Title: Re: 1989 562 head gasket....
Post by: Haymaker on June 02, 2016, 08:22:05 PM
If it is Teflon could be why your H/G failed call MTZ see if Teflon seals come with the H/G set.Maybe teflon seal was a shipping item to protect the liner surface.Let us know what you find!

Oh they do list Teflon rings like here at   http://www.belarustractorstore.com/2401003081A--TEFLON-SEALING-RING-_p_92.html   for these engines.  Best call MTZ or that parts website I guess.   Unsure of  the purpose of them, can't see this being his issue.
Title: Re: 1989 562 head gasket....
Post by: Jeff in ND on July 01, 2016, 11:31:19 AM
Finally got to cleaning up the head so I can have it checked for flatness.

Here I have only scraped old gasket residue off and wiped it down with acetone.

Rear 2 cylinders:

(http://i156.photobucket.com/albums/t5/ee-engineer/Back%20end%20of%20head_zpsawypegwi.jpg)

Front 2 cylinders:

(http://i156.photobucket.com/albums/t5/ee-engineer/front%20end%20of%20head_zpsno8p8sit.jpg)

While scraping, I found that my scraper would catch on the pressed-in injector tubes. This was especially noticeable on the center 2.  Reviewing my pictures of the old gasket, you can see where these left a impression.  Also, I note this is the same areas where the gasket rings are eaten away.

(http://i156.photobucket.com/albums/t5/ee-engineer/Is%20this%20a%20problem_zpsmhrb9bkc.jpg)


Is this normal or are these tubes protruding too far?  Also the scraper can catch on the pressed in spacers or tubes that seal the ends of that expansion gap between the cylinders.  Maybe even if not warped, this head should be surfaced?

I did talk to a person at the Milwaukee parts warehouse about those teflon rings.  Said some use them and some do not.  Also, when they rebuilt engines there, they did not use them.

Thanks for all the comments.


Title: Re: 1989 562 head gasket....
Post by: Haymaker on July 01, 2016, 02:23:09 PM
I can't remember now on my head but I'm sure it was all smooth reqarding those chambers.   Maybe give the guy a call back there in Milwaukee on that as they'd know what gives issues.  Also a head rebuilder that surfaces heads and grinds valves could tell you what needs to be done but that will cost $$.  I had mine pressure checked and resurfaced just to be sure and I think it was $300.  The valves I did myself at the nieghbors who has a lathe.
Here is a video of a guy doing his headgasket on a MTZ 82. He has a whole series of good videos rebuilding this old MTZ 82 
Title: Re: 1989 562 head gasket....
Post by: Jeff in ND on August 13, 2016, 08:33:44 PM
I had the head checked for flatness by a engine shop and was declared good.

So, I got the new gaskets and decided to get these teflon rings again after discussion with the parts depo in Milwaukee.

Last week I was at the location where the 562 is and started the reassembly.  I scrapped the block and went over it with those abrasive scrubbing pads in a drill.  I'd gotten a 14x2.0 mm tap and chased all the head bolt holes and blew out the debris.  I also ran a die over all the bolts too.  I doubt this was done the last time this
was apart.  The liner protrusion was hard to check, but as far I could tell it seemed OK.

(http://i156.photobucket.com/albums/t5/ee-engineer/Cleaning%20Block_zps3kj4feeh.jpg)

It was a pain getting this head back in place due to the dirt floor causing my hoist to get stuck as well as a post in the way.

(http://i156.photobucket.com/albums/t5/ee-engineer/Getting%20head%20back%20in%20place_zps64yabkbt.jpg)

This is a test fit of the new gasket.

(http://i156.photobucket.com/albums/t5/ee-engineer/New%20HG%20rear%20end_zpsiewjgomh.jpg)

These teflon rings are a royal pain to install.  The gasket must be totally flat or they pop up and won't stay down between the protuding
flange on the cylinder liner and the metal fire ring on the gasket.  They need to be cut to length with a razor as they are too long otherwise.

(http://i156.photobucket.com/albums/t5/ee-engineer/teflon%20ring%20install_zpscduwbljd.jpg)

Note also that there is a "top" and "bottom" to them as they are slightly warped in cross section and if put in upside down are nearly impossible to stay flat to the head deck.  They have a groove that notches to the fire ring but not strongly so and they can pop up if that gasket is not totally flat on the head.  I spent way too much
time messing with these before I got them in place and could set the head down w/o them possibly not seated and affecting the head to block fit.

After torquing down the bolts in steps I went to check the cold valve gap.

(http://i156.photobucket.com/albums/t5/ee-engineer/checking%20valve%20lash_zpsrwn3dlb9.jpg)

What should the cold gap be?  I was getting something like .037" or ~.94mm

The other thing I noted that caused me to pause my reassembly is depending on the crank rotation, there is a HUGE gap on the rocker to value that even allows the pushrod to flop around.  The rocker can be teetor-tottered a lot in this position.

(http://i156.photobucket.com/albums/t5/ee-engineer/is%20this%20normal_zpsbz8m5yoi.jpg)

As the engine was turned through all the cam positions, the valve gap would be this HUGE amount, or the "normal" gap or pushing the valves open.

I'd had all the pushrods stuck in a pc of cardboard in order so they went back were they came from (as did the headbolts).

Is this normal?  I cannot see what I could have done to cause this if not.  Seems that all the cylinders do this too.
Title: Re: 1989 562 head gasket....
Post by: Haymaker on August 16, 2016, 03:09:59 PM
So what your saying you put it all together and the valves are out of adjustment by a lot??  Could it be possible the new head gasket is a different thickness vs the old one?  Are the rocker arm shaft supports torqued down and fitting properly? You always have to adjust valves after a head removal. Adjust them according to spec spin it over to be sure all is good.  I'd have to look but I imagine they should be what .012 to .017" depending if they're exhaust or intake.  Do you have the valve clearance specs?  I can look in my book in the shop.
Title: Re: 1989 562 head gasket....
Post by: Jeff in ND on August 16, 2016, 07:58:22 PM
New gasket looked about the same as the old for thickness or close to it, didn't measure it.  I have the rocker stands down and torqued the nuts.

So far I have not adjusted anything.  I followed the manual and turned over the crank until both #1 valves were closed with small gap and I could put in the pin in the bell to flywheel per the manual.  With that, cold I was getting about 0.037" or so.  I'd have to recheck the manual but I recall spec was for HOT at something like 0.025" so I can believe that COLD would be more.  These pushrods are about 15" long so they would grow a bit hot vs cold.  While I was looking at that, I noticed another cylinder (maybe #2, don't recall for sure) had 1 valve being open and the other with this huge gap as shown.  If I rotated the crank, I could get THAT cylinders valves to be closed with the small gap and then SOME OTHER cylinder had 1 valve with the huge gap.

I doubt that anyone adjusted the valves the last time this was apart for a head gasket years ago.  I also doubt they retorqued anything either after running it a while.  I wish I knew what the tach hours were when that was.  Also wish I could find some cold gap spec's so that I had at least that right before starting it.  Doing a hot adjustment is not going to be fun.

It would seem this must be normal but sure is strange.  I am pretty sure if I tightened up that screw with the huge gap, then at the compression TDC, one valve could not close.  I was asking someone about this and they recalled some 6 cylinder Mack truck engine years ago maybe was like this.  Just seems off that the intake? rods would be free to flop about like that on what I assume must be the exhaust stroke.

But, having never seen this before I decided to stop and ask before going any farther.  I am planning to be at the tractor location in about 3 weeks or so and hopefully get it back together and running.
Title: Re: 1989 562 head gasket....
Post by: imperial1960 on August 17, 2016, 03:55:48 PM
Lets backup starting with liner protrusion! When the deck is clean lay a flat edge across the block then measure around the flange.I hold the liner down with a shorter head bolt a washer touching the liner.This will push the liner down for a correct measurement.This is best to do when liners are out to check lower counter bores. Head-gasket can fail again if you dont address this.The injector cup should not interfere with head gasket.Setting the cylinder head i use some old bolts with the head cut off as a guild to set head down onto the block.Gap on valve set remove rocker shaft bolts then lay a straight edge across all valves are they all the same height? MY MANUAL says 0.30mm for clearance for each intake and exhaust valve cold and 0.25mm hot.I use a spring loaded bolt to assist finding TDC When on TDC number one set 4 valves then roll motor over and re pin engine and set the other four valves.Did you check push-rod lengths? Can you shine a light down and check for a bad camshaft lobe?
Title: Re: 1989 562 head gasket....
Post by: Jeff in ND on August 27, 2016, 04:00:10 PM
Sorry for the delayed reply...

For the injector tubes, I tried to measure how far they stick up above the head surface with a calipers.  I could not find any obvious issues with those meeting the specs in the book.  They all were up some and none totally level or below the head surface.  No doubt some parallel blocks and a depth gauge would be the preferred way to check but I don't have those.  They all seemed to be OK and within spec.

For the liners, I tried to set a straight edge on them at the outside rim and use feeler gauges to check for how far above the block deck they were sticking up.  So far I could tell, there were no obvious problems there compared to the specs in the book.

Yes, I did find the manual shows for the valve clearances 0.3mm (.012") cold and 0.25mm (.010") hot.  I do recall the #1 cylinder seemed to be greater than 0.025" and maybe more than that (its been a couple weeks ago).  So far I have not touched any of the adjustment screws.  I am going to be at the tractor again in a week to look at this some more and hopefully finish this project up and get it running.

I now wonder what the last person in there did, maybe they loosened the valves up?  I know the push rods are approximately 15" long and thermal expansion of steel being about 6.7E-6 in/in-F means they would grow by around 0.012" going from 75F to 200F.  The rocker ratio if not 1:1 would change this at the valve tip of course.

If these are too loose by something like 0.015" or so at cold, that maybe enough at the rod end to prevent it from flopping around when the crank is at another position.
Title: Re: 1989 562 head gasket....
Post by: Jeff in ND on September 09, 2016, 08:45:25 PM
So, a update.

Last week I did get down to the tractor to finish this project up.  I determined the valves were just that out of adjustment that was causing that large gap on the cylinder that was on the exhaust stroke.  I set the cold gap to 0.015" at TDC compression for now since I will have to get in there again to re-torque the bolts and will reset the valves to spec at that time.  Rather they are a little loose than too tight until I know what is going on.

After finally getting it all together, I got it running w/o incident and after letting it run a while looking for leaks, I put on the brush mower and mowed for a hour or so w/o problems.

This may not get run again this year as fall is approaching.  The manual wants the re torque and valve adjustment to be at least warm but there sure is a lot of stuff that needs to be disassembled off the top of the engine to get the valve cover and rocker shaft off first.

The tractor has 2037 hours on the tach.  I am sure most of that before year 2000.  I also replaced most of the original hoses and coolant and oil change.  The oil was pretty new but unknown when the coolant was last changed, probably when that HG was changed last at least 15-20yrs ago.
Title: Re: 1989 562 head gasket....
Post by: imperial1960 on October 09, 2016, 05:32:25 PM
When you removed the head bolts were there any that seemed not tight? Could be lower bores in the block sounds like you got her running good job!