Valve stem seal installation

Dr.Jeff

True Classic
After reading through several related threads I did not find anything specific to this question.

In the factory workshop manual the procedure for installing valve stem seals is to use the pilot (A.60312/1) and installation tool (A.60313/2). There is a vague illustration with a partial image of the pilot, but nothing else.
Anyone know what these tools actually look like and how they are used?

Of for that matter, has anyone found a effective method for installing the seals, without damaging them, and getting them securely seated? I've noticed several old ones on my engines that were not installed properly and came loose or otherwise failed. The style of these seals is a bit different than the ones I'm accustomed to with other (non-Fiat) engines.

In this case the head is off the engine and fully stripped bear.

Appreciate any tips. Thanks
 
I found a low-detail sketch of the two factory tools, elsewhere in the FSM. But it does not help much.
 
Take the small spring off, and drop the stem seal in to a cup of hot water...wait until it gets nice and hot.

With a 10mm 12 point socket (I use a 3/8 drive) and a short extension in hand and ready, with a squirt of oil on the valve guide, with a pair of long tweezers take the stem seal quickly from the water, place it into the 10mm socket and then place it against the guide... I use a folded piece of shop rag to protect my palm the guide... and using the palm of your hand against the end of the 3/8 extension, press the stem seal firmly down onto the stepped end of the valve guide. It should go on "most" of the way...if the guide is warm and pliable this is much much much easier and there is much much much less chance of damaging the stem seal... you have to work quickly before the seal cools down and often by the time your half way thru the water needs reboiling (though I sit the cup on my wood heater in winter and that keeps the water hot!)

Personally I always put 9 stem seals into the cup... as there is a high chance of damaging them when fitting them...just yesterday I did this job and the first set of stem seals must have been old ... all 8 split and I had to open up a genuine gasket set and all 8 of those went on without issue.

If the stem seal doesn't go all the way down and bottom out, as long as the "gap" is very small don't stress about it... that last "tap" when the stem seal bottoms out is when your most likely to cut / nick the seal ... which will show up as the hole now longer looking too round... last check is to (with a strong light in hand) make sure the seal isn't split ... if it is, remove it and throw it away...and try again.

Not all stem seals are created equal, and this is one of those parts you will find much better quality parts in better quality gasket sets... the stem seals and head gasket are actually the two most "complicated" parts in a gasket set (most of the rest is just paper after all) so cheap sets usually have CRAP stem seals that just don't last.

SteveC
 
It's been a very long time since I've changed those, but did them in a similar method to SteveC.
Additionally I used an old valve inverted to push on and as a guide along with the socket.
 
Additionally I used an old valve inverted to push on and as a guide along with the socket.

I like that Idea... it would help keep everything aligned... I'm going to try this next time I fit some seals (in a couple of days time)

SteveC
 
Thanks guys, that really helps.

Looking at the little image in the FSM of the "pilot" tool, it appears to be just a round rod the same OD as the top of the valve guide, then it tapers toward the top to help center the seal as it goes down. This is the same function as Steve G's use of a old valve. I'm thinking it would be very easy to make the same "pilot" out of a short piece of round plastic rod. Perhaps even a slick, smooth type of plastic like delrin. You could turn a step into the bottom end so it sits into the valve guide to steady it while you push the seal on. Using a deep socket as your installer it will easily clear the 'pilot'.

Steve C, I've noticed several brands of VG seals offered. Which brand do you find preferred?
 
Corteco are the brand of VG seals I use... they make them in Nitrilic rubber, Viton and FPM.

Uno Turbo's use a Viton seal BTW.

Genuine Fiat are always good too... nitrilic rubber and Viton, some models use a very hard nylon looking material, big PITA to fit but work very well (expensive though).

Elring (you'll know that brand from VW parts) make nice VG seals too, again they make them in Viton if you look.

Better stem seals usually have a "ribbing" type of texture where the seal fits over the guide (no not for her extra pleasure) but to help them stay put, the top end seals have an exposed metal edge.

OK here is a picture... top Genuine Fiat NR VSS (black) middle Genuine Fiat Viton VSS, bottom Corteco FPM seal.... I tried to show the ribbing inside and the unique shape to the underside of the genuine seals... I think there must be some special machine that grips and perhaps spins the seals on.
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SteveC
 
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Thanks. Your descriptions are clear, no pics needed. I'll have to look again, but my online supplier often gives the brand name and part number, and not a lot of details (it varies considerably by listing). So with the same brand offering multiple choices of materials, I will have to see what I find under each name if it says.
 
I can send you this Doc if you want? I ran into an issue with having to reorder a set of stem seals because of completely ruining a few (from thinking it would be easy?) so I went online to see what someone who actually knew what they were doing used. Installation sets are super expensive so I made this out of a bushing from our parts X that I drilled to a 1/2" recessed area, a 5/16" drill bit as the pilot and and some JB weld. Seals fit in it like a glove. After removing the tension spring as SteveC suggested the seal slides neatly over the pilot bit, the bushing recess encases the rubber while resting on the ring and the polished pilot won't damage the valve guide. Seals go on easily and completely in line by a slight pressure using your thumb on the end. Had all 8 (from Midwest) installed in less than 5 minutes with this. I'm sure if some persuasion was needed, then simply use a dead blow hammer like the online videos where I got idea from?
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Oh, and to make sure everything was completely plumb and inline, I seated everything over an undamaged, pliable cleaned seal in one of the old heads while the JB Weld set up for 2 days. Figured that I couldn't get any more squared than using a duplicate test subject.
 
Cliff, nice job. I really like the guide to keep the tool square while it pushes the seal on. To be honest I did not fully understand earlier when someone else said something about using a old valve stem, but they must of meant something like this. Let me see if I can throw together one with some odds and ends, but if not then I'll take you up on the offer to borrow yours. Thanks, Jeff
 
I think there must be some special machine that grips and perhaps spins the seals on.
I guess the genuine Fiat ones are somewhat rare because I've never seen that "square" shape on any of my engines. I bet you are right, that shape allows some sort of machine to install them.
 
Corteco are the brand of VG seals I use... they make them in Nitrilic rubber, Viton and FPM.
Elring (you'll know that brand from VW parts) make nice VG seals too, again they make them in Viton if you look.
Looking under the Fiat part number for X1/9 seals, plus the Uno Turbo 1.3, I found a few from Corteco and Elring, plus a couple from Goetze. Some don't specify the material, but most gave dimensions. There were listings from other brands as well, but I skipped them. Viton is a brand name that I believe also goes by the generic abbreviations of FPM or FKM (see the reference link at the bottom*). Here is what I saw:

Cortico -
19018249 = set of 8, material not specified.
12014265 = individual seals, ACM (Polyacrylate).
12012889 = individual, PTFE (polytetrafluoroethylene), but not listed specific to the SOHC application so not sure if it is a correct fit. References to Fiat # 9400956059, will it fit the SOHC?
12014584 = individual, FPM (fluoride rubber), listed for Uno Turbo 1.3.
19018251 = set of 8, FPM (fluoride rubber), listed for Uno Turbo 1.3.

Elring -
553.190 = individual, FPM (fluoride rubber).
197.378 = individual, ACM (Polyacrylate).
195.592 = individual, PTFE (polytetrafluoroethylene), but not listed for SOHC specifically so not sure about fit.
294.250 = set of 8, FPM (fluoride rubber), listed for Uno Turbo 1.3.
294.110 = individual, FPM (fluoride rubber), listed for Uno Turbo 1.3.

Then there are a couple Goetze listings -
24-30667-05/0 = set of 8, material not specified.
50-306670-50 = individual, FPM (fluoride rubber).
24-30667-00/0 - set of 8, material not specified, but listed for Uno Turbo 1.3.

The ones that I stated are 'not specifically listed for the SOHC' were cross referenced from part numbers that are specific to the SOHC. Most of them give the dimensions and they appear to be the same. But that does not necessarily guarantee they fit and work correctly.

Steve, do any of these part numbers look familiar?
One odd thing I noticed is in many cases buying 8 of the individual seals is priced considerably less than buying the full sets of 8. Same material and dimensions, but perhaps they are otherwise different seals in the sets vs individual?

The "PTFE" (Teflon) ones are interesting. They appear to be for much later models of Fiat, but have the same critical dimensions. And their design seems more advanced. I wonder if any of them would be a "upgrade" for the SOHC, so to speak? Here is a illustration of one example from Cortico. You can see that it has a much larger sealing contact surface with three support rings, and being Teflon it should have less friction. It also appears to have a metal sleeve over the base:
12012889-seal-valve-stem.png


By comparison, here is the illustration for the "FPM" listing from Cortico:
12014584-seal-valve-stem.png



*In regard to valve stem seals there may be more to it than this, but here is a simple Viton reference:
http://www.zrunek.at/uk/viton/competence/fluoroelastomer/properties/difference-viton-fkm-fpm.html
 
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