Draper Valve Spring Compressor Instruction Manual Written Over

Basically all it's saying is that the tapered collets can get very firmly wedged into the tapers in the spring 'caps', enough to strain the spring compressor, if used to break the 'seal' All I do to overcome that is to fit the compressor, and tighten it. Not too hard initially, then tap the exposed portion of the spring cap to release the collets. Then finally tighten the compressor to remove the collets altogether. Mike.

Hmmm. I'm stripping down a 1970's Mazda head for a customer at the moment. The inlet valves came out reasonably easily after a whack but even the application of a large rubber mallet and a spark plug socket has failed to break the seal on the exhaust collets such that the spring compressor can remove them. I just didn't have the 4lb lump hammer to hand at the time which no doubt will do the trick when I get round to it but I'd never recommend hitting valve caps AFTER the spring compressor has been applied. You could have someone's eye out like that ya know.

Best practice is give each valve cap a whack first and you can tell as it moves that the seal is now broken and you can apply the compressor.

While I'm on the topic of stripping heads here's how to remove the old stem seals easily for amateurs who struggle. Some engines like VW and Peugeot have valve guides with serrated lips at the top to grip the stem seals. Even proper stem seal pliers sometimes struggle to get these off especially when you're working down at the bottom of a cam follower bore and can't get a screwdriver in to lever them off. What the pros do is get a camping gaz burner and fry the stem seals for a few seconds to burn away the rubber inside them. They'll then come off soft as owt. That trick will save you a lot of cursing and damaged valve guides one day.

================================== Get a small piece of wood about the size of a valve face and about 1" thick. Place the cylinder head face downwards on your bench and manoeuvre the bit of wood into the combustion chamber and under the valve you're working on so that it *just* supports the valve. Now get a socket which will sit on the valve cap but big enough to clear the collets. Now give the socket a sharp tap (not a big bash) with a hammer. This will break the joint.

The rest of the job is plain sailing as the spring compressor is really only a kind of G-clamp.

Cic.

Yes and no. If it's the type I think it is, you tighten it up to hold the valve/valve cap and then 'squeeze the handle thing' to compress far enough to pop the collets out. The release the handle... slowly!

I'm not trying to start an argument, but why do you think that? I don't suggest the cap is hit hard enough to break it. I think it would take quite a hefty bang to do that. The material they're made from doesn't shatter easily.

In my limited experience, after putting pressure on the cap with the compressor. Quite a lot, but not enough to damage the compressor, a firm tap with a 1/2 lb hammer is enough to break the seal. Only very occasionally have I had to resort to hitting the cap with a socket whilst supporting the valve. On the last 3 heads I did which were for early Celica GT4's, they all released without any problem.

Unless the valve is supported, that doesn't always work. Mike.

The collets are tapered and match a taper into which they fit, so they can wedge themselves in pretty tight. What they are basically saying is don't use the tool to attempt to break the taper. Fit it and tighten it down lightly then use a soft drift to give the seating of the collet (the thing into which the collets wedge themselves on top of the spring) a tap to unseat them.

Once collets are free, you tighten the clamp thus compressing the springs and can then ease the collets out - use the tip of a thin screw driver for this, rather than your fingers just in case the clamp should slip.

I've just watched a couple of YouTube videos on changing valve springs and it helps to see the process in action. This valve compressor has a handle that compresses as well as a 'T' bar for turning down a thread. OK not very well explained, here's a link to a picture of the tool:

- Tap the valve cap to break the seal on the locking pin/ring/clip type thing. Probably best as described by Cicero, though Haynes suggest that you hit tap the valve compression tool once it's in place.

- Attach the spring compressor in the locked position.

- Turn the 'T' bar to compress. Seems I need to ensure something and also make sure it clears something else, naturally this is what has been written over. I'm sure this will be pretty obvious at the time.

- Remove the collets (I'm guess these are the locking clips) and release the spring compressor handle (slowly). If there is enough slack remove the spring, cap etc.

Doesn't sound too difficult, just a shame it's freezing bloody cold out there. Why couldn't the HG have gone in summer eh?

Regards,

Tim

Well, when the head's off, you can take it indoors and do the valves on the kitchen table, no? This will give you and SWMBO a new and interesting topic of conversation. And then when you have to move the cooker out to retrieve the collets and valve caps which the clamp fired down there like bullets, you'll be able to clear out all that furry stuff and the dead mouse while you're there.

BTDT

Steve

I had to nip to the shops in a hurry once for a part and left the air filter housing and a tool box on the kitchen floor (a tad bit faster than putting it all in the garage). The wife beat me home and quite literally blew a gasket.

She's tolerant of many things, but not car parts in the house ;)

Regards,

Tim

I'm not talking about the cap breaking. I'm talking about the compressor slipping off the job which can happen easily enough anyway if you're not careful nevermind when you're belting the cap with one hand while the compressor is on it and under tension. Always break the collet seal before putting the compressor on the valve exactly as the instructions mentioned by the OP tell you to.

Same reason you have to be pretty careful with suspension coil spring compressors if you intend to avoid getting a strut rod rammed through your head.

================================== A bit of clarification......

The tool should be positioned so that the round part at the end of the screw sits on the valve head. The other forked end should then be sitting either side of the valve stem / collets. Turn the T-bar just enough to ensure that the tool is firmly in place and then use the lever to do the actual compression.

Since you appear to be unclear about the collets - a bit more clarification. Think of a countersink screwhead fitted into a countersink. The collets are this imaginary screwhead cut into two equal parts. They fit into a groove in the end of the valve stem.

When you compress the valve spring with the valve tool the valve cap will be pulled down by the tool and the collets will then be seen loose in the (imaginary) countersink. Pick them out with a small screwdriver or scriber and then cover the whole tool and the area around it with a heavy cloth before releasing the tool. This will ensure that you keep your eyes and protective glasses intact for further use.

Cic.

I understand you're caution, but it doesn't apply if the initial pressure of the compressor is not too high. When the valve cap is hit to release the collet 'seal', and the seal breaks. The cap should only move down the valve stem a short distance, with the collets still within it. I've never had the compressor slip, but if it did, the valve cap would simply return to it's original position, still retained by the collets.

Being an engineer like yourself, I always look for potential hazards 'before' I undertake a particular task, and wouldn't use that method unless I was sure it was safe.

I agree, but the hazard is so much greater with a suspension spring, as being safe relies much upon getting the compressors in the right place. Evenly balanced on both sides of the spring, if using just a pair of compressors, and at the right angle to suit the spring. Even so, I still treat a compressed spring with extreme caution. Mike.

I had a spring compressor fail while holding a Volvo 240 front spring, luckily I could see it starting to bend and threw a carpet over the whole lot, I stood on top of the carpet and STILL got thrown across the workshop!. Thanks to the grace of God I was not injured, nor was anything seriously damaged!! I bought better spring compressors after that !!

Mrcheerful

You should put your foot down !! I rebuilt a Lotus twin cam in the front room!!

Mrcheerful

You're a braver man than I. I'd have been out the door like a shot or hiding behind something solid out of the direct line of fire. :-) I certainly wouldn't have stood on it, even covered with a carpet.

I have two sets. A light set suitable for small hatchbacks etc, and another much stronger set for heavier cars like my SD1 or 5 series. Mike.

I would not have reached the door in time, and I figured that being above it would meant the force went sideways, which to some extent it did. I actually felt really lucky not to have been killed or maimed.

Mrcheerful

I've got some Draper spring compressors. The manual sort that you have to use a socket wrench to tighten and loosen. The problem is, no matter how slow and even I loosen one side simply wont give. So I have to keep tapping it with a hammer to get it to slip. Kinda one of those situations I wish I had a full face mask.

Tim

We were watching one of those " is born" programmes on Discovery Turbo. Probably one of the earlier series before he bought a load of garage kit. Anyway, the presenter had snuck into the house to wash a head or a rocker cover or something in the dishwasher at 1am so his wife wouldn't find out. My wife kinda went white and developed an frenzied look. Like I say, she tolerates many things but absolutely under no circumstance is anything to do with the car allowed in the house :D

Regards,

Tim

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