51 Merc auto ****** remove
- Thread starter hoffernsp
- Start date
rotorwrench
Well-known member
The Merc-O-Matic in 51 comes out in similar fashion to most other automatics with some exceptions depending on whether you are pulling the whole assembly or just the transmission housing. Just pulling the trans housing and leaving the torque converter housing makes some repairs easier. The aft mount cross member can be removed with 6-bolts and only two for the isolator mount. If you don't pull the engine, the rear of it will have to be supported. FoMoCo had a beam that bolted to the frame to support the engine. If you want to pull the whole thing out you may have to pull the floor cover plate out to make access easier but that is a job all by itself. If someone has ever pulled the floor plate before on your car, it might make the job a bit easier. All the floor sound deadener has to be scraped away fron the seams & off the bolt heads to get them out. Some cars had access plugs for the bolts but I think the 51 just has the floor cover plate.
hoffernsp
Member
Thanks for getting back. You're right the 51 floor cover does come off with about 20 screws. Now the reason for my ques is two fold 1) I'm installing the MP PB kit and I need to drill a hole in the frame behind the original brake pedal shaft for the new pivot shaft. Right now there is very little space between the side frame and the bottom of the ****** to fit a drill. 2) the ****** and car have been untouched from storage since 1973 and the ****** leaks tons.
So since the ****** is in the way and it leaks why not remove it now?
Right now the car is about 18" off the floor on stands - how high must it be to pull the ****** out from under the car?
Also I thought I'd use an engine hoist through the door on the passenger side and lower the ****** to the floor through the floor opening.
Please tell me what you think - I need your help
51 MERC-CT
Well-known member
When I installed the power booster in mine ( which appears to be the same design as the MP unit ) it was not necessary to remove the ******.
If and when you remove it hope you have a suitable jack to remove it. That puppy is heavy.
Thought at one time if I had to remove it I would consider an engine hoist as you considered.
rotorwrench
Well-known member
18 inches might be enough as long as you have a jack under the engine oil pan or something like that to support it. The floor opening is pretty big so the hoist idea should work OK. Your only problem might be the big old bell housing if you pull it too. I don't know if it will clear 18-inches or not but at least it would be on the floor. I usually get a car high enough to pull the ****** while it is on the ****** jack but if you lower it to the floor from above, you will have more room. You could drag it out on a piece of plywood or something.
hoffernsp
Member
Thanks for getting back. It's still baffling me on how you ended up drilling the 1/2 hole in the side frame? On the MP kit the pivot is 3" to the rear of the original pedal shaft and I can't seem to get a standard drill straight at it.
Any suggestions? Maybe because I'm laying down backwards and the whole world seems upside down under there
hoffernsp
Member
Thanks maybe I can squeeze another 2-3 in on the jacks. I was thinking on taking it out with the converter intact - might as well.
I have one of those low profile metal car dollies from a set I bought at one of the car shows years ago (I've since cannibalized several of the casters from them and used them on other projects) and thought I'd drop the ****** onto it from the top and maybe drag it out that way.
hoffernsp
Member
On the PB subject where on the flathead did you find a good vacuum source for the booster?
51 MERC-CT
Well-known member
Thanks for getting back. It's still baffling me on how you ended up drilling the 1/2 hole in the side frame? On the MP kit the pivot is 3" to the rear of the original pedal shaft and I can't seem to get a standard drill straight at it.
Any suggestions? Maybe because I'm laying down backwards and the whole world seems upside down under there
Did it with a 45 deg. drill motor and a 1/2" drill that I cut and ground to simulate a 'trepan' cutter.
In your case you can start with a 1/8" drill and step up until you get to your desired size.
You will probably have to purchase a 1/2" drill with a 3/8" shank if you don't already have one. Or have someone turn the shank down for you.
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51 MERC-CT
Well-known member
When I first installed the PB I was still running the stock manifold and just picked a convenient spot and drilled and tapped a I/4' pipe tap into the manifold.
hoffernsp
Member
Great I'll do the same. How did you solve the issue of checking and filling the master cylinder? I was thinking of maybe cutting out and access plate in the floor right above it.
51 MERC-CT
Well-known member
You can cut a hole in the floor if you want but I went with a remote fill master from ECI.
http://www.ecihotrodbrakes.com/remote_fill_master_cylinder.html
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hoffernsp
Member
Hello again, thanks for the info.
As I'm installing the kit I keep coming up with more questions if you don't mind.
Do I need to reinstall the pedal return spring and if so how does it attach the pedal with the new swivel fitting on the pedal?
thanks
keith
51 MERC-CT
Well-known member
Yes, a return spring is required, some imagination and fabrication is required, this is one way.
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hoffernsp
Member
Thanks, VERY nice and clean. I see that it looks like you added a brace between the pivot stud and the frame. Any special reason or just to stiffen up the pivot point stud?
On the cut out of the frame brace for the booster rod clearance did you use a hole saw or die grinder or..?
By the way I did go out and get a right angle air drill and a 1/2 in stub bit for the pivot bolt and it worked just fine.
51 MERC-CT
Well-known member
The opening was made using cutoff wheels to make slices and then break off and finish with rotary files.
The brace added for my peace of mind. (probably not really necessary )
If you are considering lowering the car these pic's show the shield that was added to protect the booster. (you can probably see the scrape marks so it wasn't a wasted effort )
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hoffernsp
Member
WOW major scrapes. Looks like a great idea. Did you reroute your parking brake cable or just run it through the notch or the half cut out on the booster mounting plate? Running it thought the cutout I noticed it adds a little bend to the cable but it does not catch on the plate but it will rub against it.
51 MERC-CT
Well-known member
Had the same situation and opted to run it thru a curved tube so that it won't rub on any sharp edges.
hoffernsp
Member
Thanks got the booster installed after tedious cutting of the hole in the frame.
Re the pedal did you replace the bushing or just left it? Mine has some metal left but having a problem finding a new one.
Also I forgot when I took it apart but does the metal stop tab on the pedal arm go below the floor board access panel?