How hard is it to remove and replace liners in a Perkins engine?

[JVM]

The venerable MF168 has blown a head gasket. That I can fix. Engine hours are unknown, but although she starts easily enough, she blows a lot of smoke, so I'm wondering if an engine rebuild is in order. Front end, gearbox, hydraulics & diff are all ok, afaik.

The last engine rebuild I asked the local tractor shop to do did not go well, so I'm wondering how difficult it is to remove the old liners (presumably dry type) and install new, with new pistons etc etc.

JV

 

[mf7480]

Easy job, the old ones are soft as butter and peel out with a chisel, the new ones drop straight in once soaked in some liquid nitrogen

 

[JVM]

Easy job, the old ones are soft as butter and peel out with a chisel, the new ones drop straight in once soaked in some liquid nitrogen

Thanks for your prompt reply mf7480. Is a deep freeze at -18C not cold enough?

 

[Lincs Lass]

Thanks for your prompt reply mf7480. Is a deep freeze at -18C not cold enough?

No where near , liquid N is - 170 ISH ??
It shrinks the liners .
No anybody with an AI flask

 

[JVM]

No where near , liquid N is - 170 ISH ??
It shrinks the liners .
No anybody with an AI flask

Lincs Lass

Sadly, no - apart from my GP who has a flask for freezing skin spots! I'm in a farming desert; no one around here does AI or freeze branding.

JV

 

[Zebeddee]

Liners will knock in carefully with a block of wood and large hammer

 

[JVM]

Liners will knock in carefully with a block of wood and large hammer

Thanks Zebedee & agrimax.

Drive them from the top or bottom? The Bareco listing mentions a "flanged liner".

JV

 

[Zebeddee]

The top the liner has a flange on the top which locates into the recess of the block and the fire ring on your head gasket seals onto that flange.

 

[Zebeddee]

The question I would be asking is why has head gasket blown? Not common on that engine to my knowledge

 

[JVM]

A very good question, Zebedee, one I've been asking myself. It blew between two cylinders about 3 years ago, so I had the head checked, and I think planed. This time I'm expecting the gasket to have failed between a cylinder and a water gallery, since the oil is slightly milky and the water slightly foamy. The tractor was well used when I bought it nearly 15 years ago; it had been neglected rather than abused. When a Welsh plug began to leak a year or two back, I found a large amount of rust around the bottom of the liner I could see. Cleaned it out as best I could, intending to use a cleaning agent followed by a glycol mix - but never got 'roundtoit - until a few months ago. Perhaps running with water only for a few years, followed by a cleaner, started to niggle the gasket. No idea if that is likely, but it's the only explanation I have. The engine has not had hard work while I've had it, usually loader and occasional backhoe work.

 

[defender]

Maybe worth knocking out some core plugs and flushing the block out if heath gasket blowing

 

[JVM]

Maybe worth knocking out some core plugs and flushing the block out if heath gasket blowing

Thanks for your thought defender. Probably a good idea, but that will be done as a matter of course if I decide to replace the liners & pistons etc.

 

[MF-ANDY]

Liners will knock in carefully with a block of wood and large hammer

Rubbish. You will need the correct sized dolly and a large puller. Yes the replacements will be a slip fit into a well cleaned block but the old ones may have been in there for 50 odd years. Which part of the less than 2mm thick liner are you thinking of hitting with a block of wood?
Splitting with a chisel may work but as I have a puller I have never tried.

 

[JVM]

Rubbish. You will need the correct sized dolly and a large puller. Yes the replacements will be a slip fit into a well cleaned block but the old ones may have been in there for 50 odd years. Which part of the less than 2mm thick liner are you thinking of hitting with a block of wood?
Splitting with a chisel may work but as I have a puller I have never tried.

I like MF-ANDY's idea of a puller; much better control over the extraction.

I've not seen one, but I imagine a plate (say) 16 thick, turned to the O.D. of the liner, with a step to go inside the liner so the plate does not slip sideways, a threaded rod up the bore with a cross bar of some sort which straddles the bore against which the nut works, yes?

I'll look at the MF135 Service manual; there might be a drawing at the back in the Churchill tools section.

JV

 

[MF CI]

The venerable MF168 has blown a head gasket. That I can fix. Engine hours are unknown, but although she starts easily enough, she blows a lot of smoke, so I'm wondering if an engine rebuild is in order. Front end, gearbox, hydraulics & diff are all ok, afaik.

The last engine rebuild I asked the local tractor shop to do did not go well, so I'm wondering how difficult it is to remove the old liners (presumably dry type) and install new, with new pistons etc etc.

JV

So two types of liner, slip fit and press fit. Slip fit are already machined to the right bore size and will be easier to fit. Press fit will need a press or proper tool to fit then need machining to the correct bore size. I have used plenty of sparex and genuine (MF original kits come with slip fit) without problems.
I wouldn't chisel out the old liners, easy to nick the block and possibly create a high spot, find, make a puller or get a machine shop to pull the liners out.

 

[JVM]

So two types of liner, slip fit and press fit. Slip fit are already machined to the right bore size and will be easier to fit. Press fit will need a press or proper tool to fit then need machining to the correct bore size. I have used plenty of sparex and genuine (MF original kits come with slip fit) without problems.
I wouldn't chisel out the old liners, easy to nick the block and possibly create a high spot, find, make a puller or get a machine shop to pull the liners out.

According to the link below, MF CI is correct. Bareco (Aus version of Sparex) lists both, and I've just noticed they offer a new crankshaft in a kit at little extra cost.

Bare Co - MF - Engine Kits - MF with Perkins A4-236

www.bareco.com.au

 

[David Bliss]

Like above said do not chisel out, done many from tractors and lorries, you need a very good heavily made liner extractor that fits or you are in danger of doing damage, then clean the the block very well, and where liner sits on the block must be scratch free, as had to repair other peoples work as gas can work down between liner and block to cause bulges in the liner and seize a piston. The hand fit liners are fine and had no problems after if done as they should be, engines that were pushed to there limits found best pistons that lasted were Alfin? that had inserted top ring land, but that was fifty years ago.

 

[MF CI]

According to the link below, MF CI is correct. Bareco (Aus version of Sparex) lists both, and I've just noticed they offer a new crankshaft in a kit at little extra cost.

Bare Co - MF - Engine Kits - MF with Perkins A4-236

www.bareco.com.au

IF the crank is worn I would rather find a good machine shop to grind it and fit a new set of bearings than fit a new crank that's more than likely been made in India or Turkey.

 

[JVM]

IF the crank is worn I would rather find a good machine shop to grind it and fit a new set of bearings than fit a new crank that's more than likely been made in India or Turkey.

I understand your concern, MF CI. Problem is, I'm struggling to find a good machine shop locally; all the old experienced blokes seem to have retired or cashed in their real estate site - or both! I have my snouts at work, but unless I get a solid recommendation, I would inclined to accept an Indian, Turkish or Brazillian, assuming the crank needs work. That dearth of workshops triggered my original post.

JV

 

[Derrick Hughes]

I remember my mate putting liners in the Freezer so the went in eisier