79 LeBaron Medallion - currently front brakes re-do.

[69-]

Some might remember my short thread about the locked up front left brake while driving to our holiday destination. A oldschool mechanic from our local AAA (-> ADAC in Germany) was able to free it up with his crowbar, but of course, it's not a permanent fix. (Thread got lost due to sever issues). We were able to get to our destination, around the area and back home without problems. On our trip back, the LeBaron had a sensational mileage of more than 23 mls/gallon! Very happy and loving the lockup-converter. But around that area (small streets, hills up and down, mostly 1st or 2nd gear) mileage was horrible - only like 13 mls/gallon. But I don't really care while enjoying driving the LeBaorn.

So, second week of vacation, doing the brakes - full re-do. Disc rotor, Pads, pistons.

Old pistons are partly broke at their pad side; I assume that dirt (brake dust) was able to get past the dust boot, closer to the piston, locking it up. New pistons are metal, not plastic (as original). The calipers show some stains, but thats no pitting, hence I assume they are ok for re-use.

The old disc rotors were different - considering the consistence of the grease inside, I'd guess the passenger side was still original and the driver side got a new disc already. The newer driver side looked pretty bad, already.

Now both are new. I was not able to finished it up, yet (passenger side - cleaning caliper and reinstalling piston). I'll finish that up tomorrow morning, as I have a barber shop appointment early afternoon (barber shop appointments got pretty rare here - due to still massive covid-19 regulations over here... Don't get me started on that topic... ).

Anyway. Here are some pictures - I always forget to make before-after pictures.
And yes, I noticed the upper ball joint, which will be due for service shortly, as well....
The browny-greasy coverage of all undercarriage metall (and all) is the sealing coat.

 

[BudW]

A great write up. The plastic piston and metal pistons can be interchanged without any issue. I have some friends who say the metal version is better and others who say plastic. I have repaired/replaced both and don't really have any opinion - but I do remember seeing something from Chrysler decades ago about no mixing them up (both plastic or both metal). Personally - I don't see a problem - but not the one to ask.

The big issue is rust in the bore. If rust free then wonderful!

Be sure to use a liberal amount of grease for those wheel bearings (which should be cleaned and re-packed every 30k miles (40k km)) - which is something that most all FMJ's (or other bodies) get overlooked.
BudW

 

[LSM360]

Back when we had the last of some Dippy AHB's on the road the very good mechanic we had always replaced the phenolic ones with steel ones. He said the phenolic were prone to pitting.

Anyone from Brevard County area might remember him. He was kind of a legendary front end mechanic Charles Barker. He was a great guy and front end specialist for decades. He had his own business "Barker front ends and alignment" and many cities and the county sent their patrol cars to him.

 

[69-]

Fixed up the passenger side today. Not in time for the barber Shop, so I had to use wife's Seat Ibiza (a little smaller than a VW Golf). Pretty tight in there. Anyway. Had to replace the new bleeder screws with the old ones, as they were still bleeding. Have to cut the tip of the cone (as the old ones have) to fit the caliper... Small Things you better look for before you reassemble it all...

Anyway, new rotors help a lot to keep the wheel straight, not wobbling around like unbalanced tires when braking. And had to remember, that new rotors and pads do stink at first - for braking and the nose....

 

[69-]

Replaced the original bleeder screws with the "cut" new ones. One side is dry, the other is still leaking... I try not to push my luck with more than 170 lbf-in (as of Service Man). Will order a set of new bleeder screws.

Picture as comparison (top to bottom): the bigger screw shows the tip at the cone, old one and the "cut" new one. As you can see I don't want to re-mount the old one. Even a 3/8 nut will seize at that rotten screw.

 

[BudW]

With 30-40 year old bleeder screws - new ones are a very good idea. Especially if you you have the fluid system open to begin with.

The plastic (phenolic) pistons are softer and you can usually see indents in it from the brake pads. I don't see that as a negative for this doesn't seam to distort anything except for the part that contacts the pad. Don't drop a plastic piston for I have damaged those before that way. I don't think dropping a precision machined metal piston is good for it, either.
Plastic is a lot better for preventing heat transfer than steel is. If you drive a car hard or towing in the mountains, then this might be a bigger concern. You want to avoid boiling brake fluid - which causes a soft/spongy brake petal and poor brake performance.
BudW

 

[Mikes5thAve]

Too bad you're the other side of the ocean where parts cost more to get cause I've always gone straight to new/rebuilt calipers over messing with the old ones.

 

[Ele115]

I always like to keep my original calipers with my old cars. I toss those GOD awful plastic pistons in the trash and buy stainless pistons. Takes me no time to clean and bead blast the calipers and zinc plate them. By then, the new pistons have arrived and I can put them back on the car and flush the lines and put new hoses on and not have to worry about it for years. The pistons are common Bendix parts. They are used in Ford, GM and AMC. Very easy to find. That plastic will warp and swell and give you problems. That's why they sell stainless steel pistons for these calipers.

 

[Remow2112]

Phenolic pistons are a great way to save weight for the 1/4 mile but they also served a purpose that water in the brake fluid would not form rust on the piston and it will continue to work even it there is rust in the bore. Kind of like the switch to aluminum master cylinders prevented rust.

 

[volare 1977]

I have had issues with aftermarket bleeder screws before with not sealing. I try to get new mopar ones if they are available.

 

[69-]

Replaced the master cylinder yesterday (of course properly bench bled). No test drive yet, as I have also opened the rear end - it was leaking and the drops of oil were accumulating. Nasty.

Because the last owner sprayed the cover in red (ieehhh), it was coverd with some Dimitrol stuff. Had to remove all that to have clean parts for mounting it. I used some black corrosion-special paint (Brantho Korrux 3in1). It is very easy to work with and very strong my cars underbodies. Unfortunately, I had no spray can of it (would have looked much better than using a brush). But who cares. You can't see the details anyway but no red.

The 7.25 looks ok'ish to me. There was no sludge at the bottom of the diff and the cover looks worse than it was. And whoever opend the diff the last time did not seal it correctly - no wonder it was leaking. So, I'll let the paint dry, remount, refill and test the brakes.

 

[BudW]

Water, rust and/or metal shavings are the thing to look for. If those three were not present - then you most likely are in great shape.

I don't need to know, but did you make note of the gear ratio while the cover was off?

Good information to make note of, while that far apart. I'm going to guess a 2.7 or a 2.9?
BudW

 

[69-]

That's a good reminder, thanks, BudW. According to the build sheet it should be a 2.45,will verify it before I'll close it again (paint still needs time).

Edit: neither of the three are present, and if it is still the original gears (considering the story known to me I Do belive that) they have less than 50k miles on it.

 

[BudW]

All factory gears have markings on them. Aftermarket gears - who knows.

 

[Remow2112]

Did they even make aftermarket gears for the 7 1/4?

 

[BudW]

Some companies did did for awhile (but not many), but decades ago.

 

[69-]

OH, sorry guys for possible confusion.

My "edit - none of the three" above related to rust, water, metal shavings (not the markings) - so, I'll just keep the gears as is. Meanwhile, paint was dry enough to mount it without getting black fingers.

Reminds me - have to put the car back into Park and remove the key (it's outside.... LOL).

Anyway, I took a picture of the numbers at the gear, it reads 372369 (missing last number as of parts book?) 2 (? my guess) 4 7 (? my guess) 1 30 78 3
The ratio marking is only partially visible. You might shed some more light into this - 2 (although the lower line is missing), 4 is ok, and the third number might be a 7 (2.47) and the dot is missing. 30 78 seems to me to be the week and year build?

 

[BudW]

That gear set must have been made on a Monday morning (hungover) or Friday evening (mind was elsewhere).

The first group of numbers should be 7 digits (the part number, blue stripe).
There are three different gear sets used in '79:
2.45 or 2.47 (ring gear stamped 3723696) - missing the last "6".
2.71 or 2.76 (ring gear stamped 2800275) - so not it
3.21 or 3.23 (ring gear stamped 2467264) - so also, not it.

The ratio (white stripe) has a faint "2" in front of the 4 - and possibly a "7" after the 4. The part number verifies it for me this has a 2.47 ratio.

Date stamp (red stripe) looks like it says "1 30 78-3". The "7" is faint. The "-3" is the shift made, so not important. They make ring gears in mass, then stop to make something else, then resume making gears before supplies run out.
Example, two weeks making 7-1/4" 2.47 ring gears, then two weeks making 8-1/4" 2.91 ring gears, then two weeks making 9-1/4" 3.55 ring gears, and so on, while another line makes the pinion gears in a similar fashion. It is odd to see this one made this much earlier than your car (a '79) - but not unreasonable either.

Either case, the person stamping the gear didn't do a very good job at it.
Bud

 

[Kramer79]

Good luck on the gears! I prob should change my fluid… where did you locate your build sheet? No luck on my car yet, I have heard under the carpet too…

That's a good reminder, thanks, BudW. According to the build sheet it should be a 2.45,will verify it before I'll close it again (paint still needs time).

Edit: neither of the three are present, and if it is still the original gears (considering the story known to me I Do belive that) they have less than 50k miles on it.

 

[69-]

I _assume_ that the original buyer had it already, mabe it was needed for registration in europe at that time in the netherlands.
Reason is because it was in very decent shape and the seller (2nd owner) didn't know anything about was it was, but luckily kept it with the car.

As the seller was neither into the details of the car nor did he mess/work on it, I think he would probably just have tossed it as junk if he would have found it.

But thats only my weird thinking . There was nothing below the rear bench when I removed it (usual location for the earlier Mopars). I did not lift the carpet, yet.