What is happening to my car?
 

84 300D I posted this issue a couple of months back in September, but I lost email and password was not able to recover my account. Since then I put the car in storage and I just brought it out.


Backstory: I did a complete brake job on my car

• ATE front/rear calipers
• Flexible hoses (front/rear)
• Cardone Brake booster
• Cardone Master Cylinder

Bleed the brakes I drove the car but brakes started to feel soggy and not in a good way. What also happened in the making the calipers were locking up (rear ones) then I started smelling a rubber smokey smell from outside the car. It felt like something was holding the car back from driving. Pulled off to the side of road, saw my transmission from below was smoking! :confused::confused:


Transmission shifts fine through 1-4 gear. P/R/D work fine

Before all this, before I even did the entire brake job the car driving so SMoooth!



Now I can't even drive the car around the block without it locking up

If the car drives but feels very sluggish and you are getting a burning smell, you may have a sticking/stuck caliper or two. Your wheels would feel pretty hot to the touch too. I am guessing it was not the tranny that was smoking but a caliper.

I assume the 300D master cylinder like the 300SD has a front and back reservoir both of which have to be completely filled to bleed the brakes. Many folks fail to get the rear one filled and that causes spongy brakes.

Dragging Brakes
 

Also ;

When the master cylinder is replaced the push rod adjustment is often overlooked .

If it has even slight pressure with your foot off the brakes it will build pressure until the car finally grinds to a halt .

Easy to diagnose : when the brake are dragging open a bleeder valve on each axle ~ of brake fluid spurts out and the brakes release, check the M/C push rod before anything else .

I know that the push rod is not supposed to be adjustable on the grilling original brake boosters but what caught my eye during installation is this new booster I bought from Cardone had a pushrod with threads.
https://www.alfabb.com/attachments/p...w-jpg.1486345/


Are these new boosters "adjustable" and what should the adjustment be? I really don't want to do a trial and error of removing the master cylinder, adjust the pushrod, replace the master cylinder, go for a drive, and repeat.

How far out should the pushrod be?

Idk I figured it was coming from the tranny because smoke was emitting from where the bell housing was, and car temp went up slightly

There is a tool for adjusting the length of the Booster Rod.
This video is for Corvette`s and Fords also that use the Bendix
brake Booster. The MB Booster looks the same, assume it should work.
Never read anything on the Forum about the tool before.


https://www.youtube.com/watch?v=qc6MgNNMQts


Another thing that will make the brakes drag, is an old Rubber Brake Hose
that is deteriorated on the inside, and not letting the fluid return. Acts as

a valve.
Hoses have a life of 7 years or so. Yeah I know some have been on vehicles
for 30 years. But the industry is 7 years like tires.


Charlie

The rebuider may have preset that adjustment right or not. If you have the old booster a comparison measurement. Between the two might be indicated.

After you make sure the rod from the brake pedal arm to the booster is not tight.

Just got up and have not had a coffee yet.

You shouldn't have to "remove the master cylinder". I think you can just unbolt it from the booster and pull it back with the brake tubes still attached since they flex a bit. I think the proper setting is so that there is just a slight gap from rod to MC piston. Start with the rod out a bit so you feel it compress as you push the MC up to the booster, then keep screwing it in until you don't feel it pushing. Also insure the pedal switch just senses movement without restricting the pedal. This is what I've done on my classic Mopar cars. I recall the M-B booster has a fixed tip, but appears some rebuilts have adjustable tips.

Brake Booster Pushrod Adjustment
 

Thanx Charlie ~ that's a *very* good reminder ~ I'm an old field Mechanic so I usually just use a thin screwdriver, it's accurate once you get a feel for it .

I like the
''BB-TOOL" referenced in the video, I wonder of they're available cheaply Chinese made at your F.L.A.P.S. ? .

Failure to check this can result in low brake pedal (too much gap) or hard to bleed or dragging brakes (no gap) .

Good tip. I replaced my tranny oil cooler lines in my 300D shortly after I got it. They were both leaking, one quite a lot. The brake lines would apparently not be as easy to spot as being in need of replacement.

I have pretty much sworn off A1-Cardone rebuilds if a known quality part is available. I bought the 126 MC from here several years ago when Roy was still taking care of things. That was after a Cardone remanned didn't work. The part from here is still good. Keep the fluid changed to prolong the life.

I do buy Cardone calipers locally. I say locally because I've had pistons lock up out of the box and have had them mis-boxed. One time a left was in a right box. Another the rears were in a box for the fronts. Rears are smaller and don't fit the fronts. This was back to back on one brake system refurb.

I buy locally in case they have to be sent back. Keep your cores until you know the new part is working well. If you give up the cores then end up returning the part for money back your cores are long gone and not available if you need them to exchange.

Update: I shortend the pushrod in the brake booster but I think the brakes are still dragging. I recorded it. In the video I try to roll the car in "P" It makes an erry noise.

https://streamable.com/sbfxbq

From that sound I would say 'yes, your brakes are dragging.' Similar to the sound mine makes when creeping forward with the brake lightly applied.

Invalid Test
 

Well ;

You cannot roll the car in PARK so who knows what that sound was .

Jack up the car and give the wheels a spin. If they spin with little resistance you should be ok. The rear will have more resistance because of the differential but all should be able to turn with minimal force.
If you keep driving it with a stuck caliper, you may damage the rotor, pads and caliper.