So I’m working on replaceing the valve stem seals on a 1972 Ford LTD (400) and ran into a problem. I went to the auto store and told them I needed the seals. They handed me a box for the intake valves and a box for the exhaust valves (8 in each box). I go home, take off the first one (an intake) and put the new one on. Take off the second one, find that it’s different then what I was sold. But it (the old one) was the same as the (old and new) intake seal. So I run back up to the store and explain the situation. He tells me that the exhaust seals should be shorter and that they may have been replaced previously and the installer put the wrong ones on. The symptoms of having a seal on thats too long arn’t present, but I take them back with me anyways. I tried to put one of the short exhaust seals on and it doesn’t fit, it’s not long enough. So as of right now, I’m just going along, putting intake seals on all the valves. Out of the 16 valves, I’ve only finished 4 so if I’m doing something wrong, it’s not the end of the world at this point. Does anybody know if they should be different sizes? Does it matter? Also I should mention… While I’ve haven’t had more then one rocker arm and spring off at a time, from what I remember I think they all look the same. That is nothing on either seemed longer or shorter then the other. So unless they travel different lenghts, I have to assume that they it would work to put all the same ones back on.
What part numbers did you get?
Seeing as the car didn’t have the “right” exhaust seals on it AND the “right” seals don’t fit, I’d say there’s a 98% probability that the either the listing is wrong in the catalog (and yes, it does indeed happen) or the counterman erred in looking it up (missed a critical footnote, etc.). It’s also possible the ones you got were misboxed.
The part numbers (from Autozone) are SS72562 for the exhaust and SS13364-1 for the intake. Here is the autozone page listing the parts I mentioned. I kinda wonder what the "ROL VALVE STEM SEALS " for $11.59 are, but there’s no pictures.
Out of curiosity, why are you replacing the valve guide seals? Did the car smoke or consume oil? If it smoked, did it smoke all the time or just at startup?
I took the valve covers off to replace the gaskets and paint them (back to orignal Motorcraft Blue). But while they were off I noticed that most of them were split open or chipped and some were just missing altogether. So on top of alot of them being broken, there’s little pieces of plastic all inside there. There also soooo brittle they’re just going to keep breaking.
And I like working on cars!
Sorry, got pulled away from the computer yesterday…
It sounds like the engine wasn’t smoking of consuming oil. At least, that isn’t why you are replacing the seals. Considering that it was running ok with intake seals on the exhaust guides, why not use intake seals this time? I assume that they’re made of the same material (actually, I assume that you did the job yesterday and this post is moot, but…)
Only got 4 of the 16 done so far. Got busy doing other things. And yes, so far I’m am just using intakes on all of them. The guy at the store said that the exhaust one’s should be shorter and if I use longer ones they could get pushed down too far and and up splitting. BUT if that’s the case all the exhaust ones should be missing. They’re sooooo brittle they snap just squeezing them between your thumb and forefinger. So I’ll probably just put intakes on all of them. Oh, one more thing. There woulnd’t be any harm in (carefully) using an impact wrench to loosen the rocker arm bolts I assume. They’re on REALLY tight and I’m going to end up breaking either the rachet or the bolts if I keep hammering at the rachet arm. Okay, yet another question. When I take them apart (remove bolt, rocker arm, oil splash thing, fulcrum, spring keepers, washer, spring, pushrod… I clean them all. Should I be coating them in clean oil before I reassemble (at least pushrods and rocker arm parts)? Or will they get coated enough on there own? ONE last question (you know I feel really naive asking all these questions, it’s just because the chilton book is like 1000 pages and I get tired of flipping though it.). The bolt holding the rocker arm is VERY tight. When I reassemble I should be tightening it all the way back down correct. I’ve noticed that some of the times when I crank it back down it will open the valve a little (I have an air compressor hooked up to it and I can hear the air move when I tighten it), but a loosening and tightening it a couple of times tends to stop that, I assume it’s just not sittting on the valve stem just right. Anyways, do I have to worry about adjusting anything, or do I just tighten it all the way?
Well, I’d rather be there to answer most of your questions, but I’d use assembly lube or at least STP when going back together. As for the impact wrench, I don’t really like them, but that’s just my personal opinion.
Well, as for the impact wrench. I loosend the remaining 12 bolts in under a minute. Probably would have been closer to 10 or 20 with a rachet and mallet. I only finished two more seals and I just dipped the ends of the pushrods in oil. Even with as clean as I got all the parts, there was still an oily film on them, so I think they’ll be okay. (I hope).
My local Carquest store (very sharp personnel) shows the same valve stem seals for both intake and exhaust valves for a '72 LTD with a 400 (code S) engine. Apparently the listing you’re working with is in error. Now the only question is whether the intake valves you’re using are the correct ones. Since the appearance and fit seems to be the same as the old ones, it’s a pretty good bet they’re the right ones, but it wouldn’t hurt to double-check.
The slight opening of valves you describe when installing the rocker arm nuts could be explained by the action of the hydraulic lifter. By loosening and tightening the nut you’re compressing the lifter a bit. You don’t need to do that. It would be wise to make sure the rocker nuts are tightened to the correct torque.
A light coating of oil is sufficient for those parts, which are broken in to each other (and of course everything should go back to exactly where it came from, which is automatic if you do them one a time). If the parts are oily and not dirty, it’s not necessary to clean them or oil them. If you clean them, oil them.
I figured I was just pushing the valve down a little. What do you mean by “you don’t need to do that?” I don’t need to go back and forth to get it right? Assuming that’s the case, then is it safe to assume that once the enigne turns over a couple of times everything will kinda seat back into place. As for tightening them to the correct torque, dumb me forgot about that altogether. I even just bought a torque wrence (for something else, but I have it none the less), I’ll go back and re tighten the one’s I did.
Correct.
Just be sure to loosen them first. A torque wrench is designed to measure while the fastener is being turned and tightened. It will not give meaningful results if applied to an already tightened nut or bolt.