Pan Gasket Squeeze Out

[Tmac897]

Rebuilt the bottom end of my engine, and getting the covers and pan back on. I sealed the pan gasket with Permatex High Tack gasket sealer. Tightened all the pan gasket bolts gradually, eventually to 6 ft-lbs, which is the low end of the recommended setting. Got some gasket squeeze out around the bolts, and especially at the corners. Gasket seal has of course set now.

I’m kind of at a crossroads. Do I remove and start over, or am I being too careful?

Thoughts?

[oldelanman]

Did you check the sump flange for flatness before you refitted it ? If the bolts have been overtightened in the past there may be some distortion around the bolts holes so it doesn't sit flat against the block face .. that could be causing your gasket to squeeze out.

[elans3]

I'd take it off again, straighten any previously overtightened holes, and re-do it.

[tvacc]

I dont know....looks ok to me. I have put on many a pan and mine always look like that...but I use RTV. Actually the best stuff I have ever used and what I use all the time know is "the right stuff". I have never had a leak with that stuff. But I am not an expert mechanic so who am I to give advice.

[pharriso]

yes, re-do it. Easy enough to do it now... you don't want it in the car marking it's spot on the driveway...

I am sure Rohan will be along with his gasket sealant recommendation... I prefer Dirko Sealant....

[RichardHawkins]

Tony,

One of the previous owners of my S4 Elan was strong and rough. All the head bolts were stretched, as were the cam cap studs. The cam cover was crushed and cracked.

The pan bolts had been over tightened, and the pan was distorted. I spent a long time straightening the pan flange and made 1/8” thick washers for the pan bolts, as large a diameter as will fit (5/8” if I remember correctly). I trial fitted the pan without a gasket and used a 0.002” feeler to check if the pan was flat. I took advice from Rohan, I think, and fitted the gasket in two stages, first I stuck the gasket to the block, lightly bolted the pan down then waited for the gasket sealant to set, took the pan off sealed the pan then re-bolted. This stops the gasket extruding as it is effectively stuck to the block. As for the sealant, I used a grade of Loctite but cannot remember which one, I can search that out if you want to know. By the way Rohan also advises being cautious with the sealant, as you don’t want surplus sealant inside your engine stuck to the strainer in the pan.

Hope this helps,

Richard Hawkins

[Tmac897]

OK, I pulled the pan off and started checking for “flatness.” Luckily, the pan edges seem pretty flat. However, all of or most of the bolt holes are raised up, and when a straight edge is placed over the centers of the holes, I can see lots of daylight.

So my assumption is that the previous owner had a pan oil leak, and his solution was to tighten down the bolts, which distorted the area around them. Didn’t think to check that before reassembly. Better to find it now though.

Now the next job is to suppress the urge to take my 3lb hammer out and bash them back down.

[2cams70]

Smear only a very thin layer of RTV on both sides of the gasket and the corners of the front and rear oil seal carrier cork strips. You then need to fit the sump and loosely tighten up the bolts so there is contact but minimal pressure against the gasket sealing surfaces. Allow the RTV to cure overnight before fully tightening up the bolts to the correct torque (use a 0-25Nm torque wrench). This will prevent gasket squeeze out on silicone that is uncured and therefore slippery. It goes without saying that you need to ensure the sump flanges are flat before fitting.

Note there is a specific sequence in the Workshop manual for tightening up these bolts. I'll upload the relevant section later.

[Foxie]

Smear only a very thin layer of RTV on both sides of the gasket and the corners of the front and rear oil seal carrier cork strips. You then need to fit the sump and loosely tighten up the bolts so there is contact but minimal pressure against the gasket sealing surfaces. Allow the RTV to cure overnight before fully tightening up the bolts to the correct torque (use a 0-25Nm torque wrench). This will prevent gasket squeeze out on silicone that is uncured and therefore slippery. It goes without saying that you need to ensure the sump flanges are flat before fitting.

I'd second this absolutely.

Also, change to Allen Key socket bolts to make this job a doddle.

[rgh0]

In general I agree with all the above but a couple of additional cautions for what they are worth.

1. The Permatex hi tac gasket sealer is a suitable sealant in this application but I would use a small dab of silicone sealant ( use the high temp red or copper varieties) in the corners where the semi-circular crank seals join the flat block seal strips to fill gaps there. I would not use use silcone sealant on the whole gasket assembly as to much risk of being heavy handed and using to much and to much getting inside the engine. I also see overtime the cork squeezing out if using silicone sealant to try to hold a cork gasket in place even if it works OK initially, just my personal observations other may have it work OK and thats fine

2. Allow the gasket sealant to go off and set a little before seating the pan and compressing the gasket. I do both sides by doing a thin layer on the block side of the gasket waiting around 15 minutes and then placing it down on the block then doing the other a layer on the gasket face and wait another 15 minutes. I then lightly compress the gaskets to seat the pan and gaskets in place. You normally need to compress the cork semi-circular gaskets a fair bit until the pan just sits on the flat gaskets and only slightly compresses them to about 95% their original thickness i.e 5% compression. I then wait overnight and tighten down the bolts working from the centre out in a criss-cross pattern the next day. Rather than work to the torque specification I aim to compress the gasket to evenly 70% - 75% of its original thickness i.e. about 25% to 30% compression when it is fully tightened. Compressing more than this can lead to the gasket extruding out as you start to distort it rather than just elastically compress it.

3. I use socket headed cap screws with the largest flat washer I can fit and a spring lock washer as that makes it easy to get to them once the engine is in the car. I would go back and check the tightness of all the bolts after a few engine heat cycles but try not to further compress the gasket much further. However depending on the actual gasket quality ( and they vary) you may find you need to compress it a few percent further to get the bolts tight enough not to work loose. I debate with myself as to whether I should use a thread locker on the sump bolts after this final tightening check but I find its normally not necessary as the gasket and sealant tends to also act as a thread locker.

cheers
Rohan

[Tmac897]

Thanks for the detailed reply. Although it seems to work for some, I’m not considering RTV for this application, except in the corners. Too many horror stories about clogged oil pump relief valves for my liking.

But I do think I’ll switch to Aviation GS #3 as you recommend in your post on installing rope seals. Used that on the paper gaskets and it does seem a little stickier when set up.

Is there any particular grade or type of metal socket cap screw you use? Longer length to accommodate the additional flat washer? I went to a 3/4” length for the two bolts nearest the front semicircle seals to get a little more thread bite before there was much pressure on that joint, since it’s into aluminum.

Best,
Tony

[2cams70]

As promised refer attached extract from the workshop manual for the correct sump bolt tightening sequence once the sump is bedded down in position and RTV allowed to dry overnight

Step 1:
Tighten bolts in alphabetical sequence A, B etc. to R to 5Nm
Tighten bolts in numerical sequence 1, 2 etc. to 18 to 5Nm

Step 2:
Tighten bolts in alphabetical sequence A, B etc. to R to 11Nm
Tighten bolts in numerical sequence 1, 2 etc. to 18 to 11Nm.

Stop at that point. Do not be tempted to go over the bolts again at 11Nm. Cork is a funny material. If you keep going over the bolts even with the torque wrench set at a fixed setting the cork will keep compressing and become overstressed. Do not be tempted to keep going over the bolts "just to be sure".

A couple of other points:
The 1215 Threebond RTV works great here. It's a "slump" grade RTV which means it's easy to spread thinly like butter over surfaces with your finger. It both sticks and seals very well. The good adhesion properties mean that the cork is firmly stuck in place and won't extrude (provided you do the bed down overnight cure before final tightening). "Slump" grade also means that if it extrudes it rolls over surfaces like a bead of water and adheres so there's less chance of it becoming loose inside an engine. Thicker grades on the other hand do not roll over surfaces if extruded. Large beads of RTV therefore hang in mid air held up by only a thin sliver of RTV material liable to break and release the beads of RTV into the engine. You don't get large beads of course if you only use a minimal amount. The other good thing about the 1215 is that it has a long tack free time which allows time to properly set things up before it cures. This is good for DIY. Many RTV's are formulated for production line use and have a much shorter tack free time.

The OEM Ford fasteners are best!! On 711M block engines at least the spring washers Ford used on sump bolts are not a standard 1/4" size. They are larger in diameter, thicker and stiffer in tension than regular 1/4" spring washers. Best not to use flat washers under spring washers (Ford didn't) because this inhibits the ends of the spring washers from digging into the parent metal surfaces for mechanical locking effect.

Picture of result attached - note hardly any extrusion of either cork gasket or RTV

[Tmac897]

Thanks for the info. Very helpful.

Best,
Tony

[Panda]

Tony Ingram (lotus7.com) sells an oil pan stud and bolt kit part number TCP-SBK for $28.00 which aims to fix the problem. But won't fix overtightening. He also has a good website.
Alan P.

[2cams70]

For your reference:
Pictures of a standard 1/4" spring washer on the left and and an original Ford OEM sump bolt spring washer on the right. Use these together with original sized 1/4" UNC x 1/2" long bolts and no plain washers correctly torqued in all 18 positions and you won't have any problems. The difference between regular spring washers and the original Ford ones is clearly obvious!!