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Overhead Valve Spring Compressor - Best

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#1 ryomini

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Posted 15 June 2019 - 11:23 PM

I am soooo tired, body aches everywhere (I recently took up sup surfing, and sometimes I forget that I am 54 years old !)

 

I saw a good post I believe by mokespider (over in Australia - is that right ?) and was wondering as new things come up all the time - what is the best / easiest way to change the rubber valve seals with the head IN PLACE.

 

There was a picture of the hooked mazda engine tool (i'm guessing it grabs the back of the head ?) and I have seen some universal bolt on tools - but it needs to be firm and smooth otherwise it's very fiddly if you are working alone

 

has anyone had a lot of success with something - I would like to have a look as I want to change my seals but don't want to pull the head right now  (I see those screw down ones used on the american muscle cars, but some of them have very 'soft' springs and sizes may not be the same)

 

thanks

 

a tool like the one in this vid

 


Edited by ryomini, 16 June 2019 - 02:19 AM.


#2 gazza82

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Posted 16 June 2019 - 09:06 AM

I use one similar to this type ...

Attached File  7F461FE4-4E9F-4405-BCC7-4C7070E7B544-huge.jpg   19.57K   0 downloads

But mine is a few decades old ...

#3 johnR

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Posted 16 June 2019 - 09:40 AM

I presume you are looking for the type that allows you to change the seals without removing the head?



#4 ryomini

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Posted 16 June 2019 - 10:25 AM

@johnR yep that's right - in the youtube vid the guy has the tool but he has the head OFF.  @gazza82  I have a similar home made one but it won't work with the head ON.  I was interested to get other mini owners' experiences of changing valve seals with the head ON, some tools work way better than others and save lots of hassle - cheers for the feedback though



#5 gazza82

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Posted 16 June 2019 - 12:50 PM

Sorry missed the head on bit.

I've heard that threading thin rope into the compression area can stop the valves being compressed if you can push enough in.

Edited by gazza82, 16 June 2019 - 12:51 PM.


#6 andyapanel

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Posted 16 June 2019 - 02:57 PM

Sorry missed the head on bit.

I've heard that threading thin rope into the compression area can stop the valves being compressed if you can push enough in.

 

I remember reading an article on it in Car Mechanics about 30 years ago

I guess its one of the things professional mechanics know how to do successfully. I am not that brave: I go the head off, standard decoke route. You may as well clean the head while you are at it.

Good luck with whichever route you go down.



#7 Moke Spider

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Posted 16 June 2019 - 08:26 PM

 

I saw a good post I believe by mokespider (over in Australia - is that right ?)

 

Hey Surfer Boy!

Thanks for the mention here but this time, I'm not guilty !

 

I do know of the type of tool to which you are referring, and on an A Series, it would likely work from a bare rocker shaft. I tend to think though, the types of tools shown in the video would be less of a fiddle. I don't have an 'on car' tool for doing these.



#8 ryomini

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Posted 16 June 2019 - 09:14 PM

@gazza82 the rope just stops the valve from dropping down, so effectively it is compressed by the piston and the rope, the problem is usually getting the collets off is much easier than getting them on and if the valve isn't high up and seated it will be hard to get the collets back on and then yes - you are very stuck!

 

@moke cheers, as the tools are only about 10gbp these days I might pick one up and see how it works and if I have a spare gasket on hand can always pull the head if things don't work out.  It seems to be becoming more popular especially on high mileage Japanese cars (not minis) to reduce smoking



#9 Moke Spider

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Posted 16 June 2019 - 09:36 PM

The other way of holding the valves up is there is a fitting you can buy that's fitted to the spark plug hole and then connected to an Air Line and Air Compressor. You need to rotate the engine so that that piston is at BDC first though or you can be in for a rude surprise 1/2 way through the job.

 

With either technique, it's probably a good idea to re-fit the rear cylinder head nuts, just nipped up, before doing the job.

 

Yes, the 'modern oils' that lack Potassium (I think!) do cause the stem seals to dry out and become brittle. They can usually be rejuvenated, good as new, by a soaking in very hot water.



#10 ryomini

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Posted 17 June 2019 - 01:30 AM

@moke I was going to use the rope method (about 3 meters worth in the plug hole) and then bring it up to tdc on the compression stroke, you only have to do it four times, the real hassle is you have to repeat the spring compressing 8 times, and not lose a collet along the way - haha

 

@moke have you established any correlation between worn valve seals and oil consumption in minis ?


Edited by ryomini, 17 June 2019 - 01:57 AM.


#11 Moke Spider

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Posted 17 June 2019 - 07:27 AM

 

@moke have you established any correlation between worn valve seals and oil consumption in minis ?

 

Gotya on the Rope method. That works fine - as long as you don't want to tie up your wife's present with the rope after :D

 

I've not found too many seals over the years that have actually been 'worn', but usually gone hard or split or cracked.

 

These seals don't have a big 'take up range' to them, so it only take a bit of wear in the guides and no matter how new or good the seals are, there'll still be leakage past them, much like the Rod Shift Gearboxes. With Guides that are in perfect condition, you can pretty much get away without Seals, though, it's not something I would recommend.

Generally, while some Oil consumption can be experienced past the seals and down the guides, usually most oil consumption is past the rings. I know that worn bores and rings spring to mind with this, but sometimes it's from gummy rings too. A change of Oil to one with high detergents, like Diesel Engine Lube Oil, can be helpful here.

Also, and again, generally speaking, when the Guides are worn to the point that they are leaking, resulting in increased oil consumption, the rest of the engine & gearbox isn't too far behind.



#12 hungdynasty

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Posted 17 June 2019 - 08:07 AM

I did the stem seal few years ago using this DIY successfully, for your reference, please don't laugh.Attached File  1560758471543.jpg   33.04K   4 downloadsAttached File  1560758427329.jpg   25.83K   3 downloadsAttached File  Screenshot_2019-06-17-16-05-18-387_com.miui.gallery.png   321.01K   3 downloads

*Let me explain a bit, I bought a regular compressor tool, desemble the "pusher", fixed it on a long steel bar, then placed one end under windshield with a piece of foam in between as cushion, the other end under your arm , "pusher" on top of spring, it was pretty easy to compress and remove with rope method.

Edited by hungdynasty, 17 June 2019 - 08:39 AM.


#13 grizzler73

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Posted 17 June 2019 - 03:15 PM

You got a drill press? I have a plate with slot in it that fits around the retainer and a hole to the side with a bolt and nut fixed in it. put that in the chuck

and hey presto, a valve spring compressor! You also need a wee bit of wood to put under the valve. I nicked it off that Jamal chap on YouTube.



#14 DeadSquare

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Posted 18 June 2019 - 06:23 AM

You got a drill press? I have a plate with slot in it that fits around the retainer and a hole to the side with a bolt and nut fixed in it. put that in the chuck

and hey presto, a valve spring compressor! You also need a wee bit of wood to put under the valve. I nicked it off that Jamal chap on YouTube.

 

How do you drive the Mini under the "drill press" ?



#15 ryomini

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Posted 18 June 2019 - 01:20 PM

@ nasty - that is brilliant - did you bend the scuttle (i think that's what it's called) at all ? it's pretty thin.  You should get a lot of leverage out of that, but you did it all yourself, pulling on the bar and putting the collets back in with your other hand - wow you are very coordinated !

 

@grizzler - that Jamal guy is the dude - I watched all his flywheel pulling videos and they were such a help - lifesaver :)

 

@moke tie up my wife or the present ?


Edited by ryomini, 18 June 2019 - 01:23 PM.






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