1970 Mopar Mystery

[KZ4406]

Hi everyone

I haven't been here for awhile because everything has been ok with my car, a 1970 Dodge Challenger RT/SE 440-6 that I had a full restoration done a few yrs ago. The car has 44890 original miles and I only drive the car a few times during the yr. Car is stored in a climate controlled air bubble and I have driven about 200 miles since the restoration. Engine is pretty much stock, but I thought I would change the oil and oil filter just to be safe. I drove the car for about 20 minutes to get the oil good and hot, car ran great, everything is as it always was.

I jacked the car up on the driver side lifting point as illustrated in the Dodge Service Manual so that the left front wheel was about 4-5 inches off the ground, where I could slide under the car and remove the drain plug. Oil and oil filter change were non eventful, I lowered the car, started the car up and checked for leaks. I then put the car into reverse so I could reposition the car to put back into the garage and felt the brake pedal was extremely stiff, something not right, and, I had no braking power! The guy who restored the car had used silicone brake fluid so that if there were any leaks, the fluid would not corrode the painted parts under the car. The downside is that you get a slightly softer brake pedal, but the brake pedal after the oil change was much stiffer. Even when I pumped the stiff brake pedal there wasn't any braking!

It's a mystery to me what could have happened. The brake master cylinder is on the driver side and the only thing I can think of is that the car was jacked high enough to shift the fluid in the master brake cylinder enough to maybe let air into the cylinder? I did not remove the master brake cylinder cap to check the fluid level because it is a Gold OE restoration and I was concerned I would scratch the cover so I cannot tell you what the level in the master brake cylinder is but there were no leaks around the cylinder, everything is still pristine.

Has anyone experienced this before? I would appreciate any feedback from you folks. Thanks

P.S. Yes, power brakes, front disks, rear drums, sorry about leaving out those details, also, I had the parking brake engaged when the car was jacked

KZ

 

[pschlosser]

I agree there isn't much in common with an oil change and power brake function. How these two are related is a mystery.

a stiff power brake pedal sounds like little or no vacuum boost to the power brakes. so a recheck of the vacuum supply line from the intake manifold to the brake booster is in order.

 

[floyd]

Did you crush the brake line when you jacked the car up?

 

[Challenger RTA]

Bad rubber line? frozen calipers and wheel cylinders.

 

[Steve340]

Just my personal opinion - I avoid jacking any car up in a way that twists the chassis or body.
I always jack my car up either under the K member or the rear axle housing.

 

[KZ4406]

I agree there isn't much in common with an oil change and power brake function. How these two are related is a mystery.

a stiff power brake pedal sounds like little or no vacuum boost to the power brakes. so a recheck of the vacuum supply line from the intake manifold to the brake booster is in order.

Thanks, I will double check

 

[Bret Schneider]

Crushed brake line going to the rear brakes is a possibility.
The brake line is routed past the lift point you used. If it were crushed completely without cracking the line it would have the same effect as putting a plug in the rear master cylinder port. Instant hard brake pedal since most of the normal pedal travel is a result of expanding the rear brake springs when the brakes are applied on a drum system.

 

[KZ4406]

I would have thought that if I had crushed a brake line then there would be fluid leaking from somewhere?

Since the car is in another state, I will check all suggestions/comments when I return to the car, not sure when that will be, that is why I am being pre-emptive with my Q's

thanks for the replies

 

[moparlee]

These are all good suggestions. I would also suggest that you drive the car to keep everything working as they should. And don't be afraid to remove the master cylinder cover as you may have to remove it anyway depending on what the issue is. And we need pictures of your Challenger!

 

[KZ4406]

Since you folks have been so generous with your helpful suggestions, per the request of MoparLee, here are some of the many pictures I have of the car. I bought the car a few months shy of my 21st birthday in May, 1981, odometer read 43000 miles. I bought the car from the 2nd owner who only had the car 1 yr, he was a student in law school and needed $ for books, price was $3750, a lot of money now, was even more back then for a starving 21 yr old. Painted the car right away from the brown to a banana yellow, added black 71 RT stripes, I have always liked the yellow/black combo and also hemi-orange /black color combo added T/A rear spoiler, black on the hood and Keystone raider wheels. Over the yrs I putsy fu**ed around, car was 80-90% original, numbers matching, but then June 2014, decided I wanted to restore back to OE condition, odometer read 44827. Wow was I in for a surprise! The prices for OE and/or date correct parts almost had me cutting back on how far I took the restoration. 4.5 yrs later, I had the car back, and in November 2019, I had the car towed to the MCACN show because I had wanted to know how well the car had turned out. Dave Wise judged the car, 985/1000, Gold OE, and since then I have tweaked a few easily remedied items so I am sure the car is at 990, that is good enough for me. I also have Dave Wise's 47 page inspection report certifying the car as being correct. I have a ton of before, during and after pics but will limit myself to these few pics. Hope you enjoy them. Currently, I keep the car under a soft car cover encased in a car bubble, battery is out of the car on a trickle charger. I did not want a race car, I wanted the car to be as close to OE as possible, so the engine is basically the same, 410HP, 490 ft/lbs of torque. She purrs like a kitten but will go like a scalded cat if you ask her to. Current odometer is 44910, I am trying like he** to keep under 45000 miles but the 20-25 mile trips I take the car out on are starting to add up. Outside in the sun the dark burnt orange almost looks like a candy apple red, but under florescent lights, an ugly brown, one of the pictures shows what the car looks like under the outdoor sun vs being inside at the restoration shop. Dark burnt orange is not my favorite Mopar color but that is what the car's color was in 1970 (actually, 12/1/1969) so that is what it was restored back to.

 

[KZ4406]

A few more pics, I was limited to 10 pics

 

[Mopars & Missiles]

You do have a very nice car, but at 66 yrs old, you better start thinking about "driving and enjoying" that car while you still can. Your health can and will change quickly, especially after you hit 70. Trophy's and point totals are really meaningless compared to enjoying the car while you're still able to breathe.

 

[KZ4406]

Jah, I am beginning to see that, once I figure out this brake issue I will get her back on the road, since the restoration she has seen not one drop of precipitation, I only drive her on perfect days, no puddle on the road, etc. She is as perfect as the car can be considering she is 56 yrs old (young?). BTW. the window sticker showed she was a "dealer demo"