My 1965 4spd has been sitting in the garage for two years due to a back injury. Got it started OK, but it acts like a very heavy load to get the car moving. I don't see problem with the brakes - the rear wheels will move freely by hand for a fraction of an inch which offers some indication that the service brakes are not a problem Transmission works in that it will shift into neutral and forward and reverse. I feel like it is in the rear end. What steps do I take to narrow down the source of the problem. I have had the car for 30 years and have never done anything to the rear except brakes. I do all the work my self and mechanically inclined but need to have specific instruction when doing something for the first time. I have taken oil from diff. and was thinking about putting in some lube with additive, but doubt if this is the problem. Any ideas where to start?
-
-
Re: Too much power required to move car from stop
My first guess would be the parking brake(s) are rusted to the rotor; however it also could be the front service brake(s).
To check the parking brake: (There are step by step instructions in your copy of the 1965 Chevrolet Service Manual.)
Remove a rear caliper from the caliper mounting bracket. & hang it out of the way (not by the rubber brake hose)
If the rear rotor has never been off/changed before you will find two rivets holding it to the drive flange. Those will have to be drilled off. Be sure to mark the rotor and the drive flange (or one of the wheel studs) so you can reinstall the rotor in exactly the same orientation as it was before you started. If the rear rotors have been off/changed you may find two flat head screws holding the rotor to the drive flange. Or you may find nothing holding the rotor on.
Remove the rotor to expose the parking brake mechanism. If the parking brake it the problem removing the rotor will be a very difficult process. You will know before you get the rotor off if they are your problem.
The results of this exploration will indicate what further action is needed.Terry -
Re: Too much power required to move car from stop
Ken, put car into neutral and see if the car will roll, If not as Terry says head to the brakes, jacking one tire at a time and try to see if each wheel will spin. Sometimes also, if the disc pads are of the metallic type they can rust to the rotor (s).New England chapter member, 63 Convert. 327/340- Chapter/Regional/national Top Flight, 72 coupe- chapter and regional Top Flight.Comment
-
Re: Too much power required to move car from stop
Terry - Thanks for your reply. I am very familiar with the parking brake assembly having put stainless brakes on the car about 30 years ago when it failed inspection. Doubt if it is the service brake after looking at the clearance between pads and rotors. I thought at first it was the parking brake sticking, but it seemed unlikely that these relatively weak brakes could hold on heavy acceleration - will check it out for sure. I will take it step by step and let you know what I find. Best regards, KenComment
-
Re: Too much power required to move car from stop
Another thing to check is the compensation port in the master cylinder. On a '65 it's a tiny hole that can easily develop clog or obstruction. The symptom is brakes that won't release properly after being applied. They will release however after the car sits for a short time.
MikeComment
-
Re: Too much power required to move car from stop
ditto for the brake hoses at each wheel. They will act like check valves because they collapse inside due to age.
Stu FoxComment
-
Re: Too much power required to move car from stop
Thanks for the input. The problem is solved. I took off the calipers and rotors and was able to easily spin the rear axles by hand. The parking brake shoes were stuck tightly closed to the rotors due to corrosion somewhere. Fortunately I put stainless steel parking brake parts some time ago. I will clean all the moving parts to get every moving freely. If the rotors continue to bind against the loosely adjusted parking brake shoes, I think I will get the rotors turned to get more clearance. Maybe they got of out round from overheating? Thanks for help. Best regards, KenComment
-
Re: Too much power required to move car from stop
If the parking brake shoes were truly jammed against the drum, you would be unable to remove the rotor from the spindle. Being able to turn the half shaft does not mean there is no other potential problems with the diff.
I don't think you're out of the woods yet.Comment
-
Re: Too much power required to move car from stop
Don't be scared by the naysayers or overthink the problem. If you have freed up the parking brake, put the wheels back on and drive the car checking for any abnormal heating at the four corners.Comment
-
Re: Too much power required to move car from stop
There was a time when one of the complaints about the stainless steel parking brake shoes was that their curve was not the same radius as the inside diameter of rotor hat. This made them less effective than the stock shoes, which are marginally effective to start with. This situation may or may not have been remedied over the years, and may or may not have any thing to do with your current situation. I just offer it for your edification.TerryComment
-
Re: Too much power required to move car from stop
Hi Ken: When you say "problem solved" does that mean that you no longer have the problem (sory for asking the obvious, but ...) If you haven't solved it or tried the road test. then I have a recommendation on diagnosis:
Car up on jack stands
Wheels etc installed as normal
Disconnect half shafts
Spin each wheel manually
The should turn with slight drag. You may have to turn them a few times to push the pads from the rotor.
This should at least tell you if you have a problem with either or both wheel assemblies (brakes dragging etc)
If either or both are difficult to turn the you've isolated the location if not the cause.
If both turn reasonably freely then your issues are further up the drive train and you can start eliminating those by isolation. Example: If the wheels spin freely and you connect the half shafts, then disconnect the drive shaft and try it again. Remember you are adding parasitic drag with each component so when you connect the half-shafts you are turning the differential and BOTH wheels so it will be tougher. Umm: Re-thinking this, you might even connect one side at a time to detect potential issues within the differential. Apologies if you've already done this, but I didn't see any of this in the thread...Regards...joe
One more thing: I STRONGLY recommended NOT running the car up on stands...Explanation not required...jtComment
-
Re: Too much power required to move car from stop
Hello All and Thanks for the replies. I took off the rotors (had to tap one off with lead hammer) and examined all parking brake parts. Did the normal adjustment procedure and was confounded by the results - sometimes wheels moved freely and parking brake worked but remained stuck when parking handle was released. Released the tension on rear cable and found that the cable was rusted and would not always release brake shoes. Cleaned everything up and rebuilt calipers etc. OK now! I feel stupid asking for help without checking all this out at the beginning. I remember a phrase "Occam's Razor" that loosely translates to "The simplest and obvious solution is usually the right one."Comment
-
Leif
'67 Coupe L79, M21, C60, N14, N40, J50, A31, U69, A01, QB1
Top Flight 2017 Lone Star RegionalComment
-
Re: Too much power required to move car from stop
My recommendation is to not use the parking brake if the car is in storage for more than a month. I just leave it in gear and double chock a front wheel.
DukeComment
Comment