Was it the brake fluid?

[Jimmys66]

I did the full cobra brake swap (front and back) onto my 66 using the 03 m/c. It had great pedal feel and pressure. I swapped the rear factory lines for a set of s/s braided lines and changed the brake fluid to synthetic.

Now the pedal is very stiff. Not unusable but, stiffer than I'd like. Before I changed the lines and the fluid it didn't require alot of pressure to put the car in full lock.

Any opinions?

 

[CraigMBA]

I think I'd try rebleeding the brakes.

The pedal should feel the same unless you have some sort of obstruction, in that case the pedal will be rock hard and you'll have reduced braking force.

 

[ForceFed70]

Something weird is going on there.

I don't think the lines, or the fluid could cause this.
The stainless lines will usually make the pedal feal more stiff, but shouldn't effect pedal effort.

 

[BlwnGazkit]

Unless he had a bulging rubber line before and now he's feeling the extra stiffiness from the new lines...

 

[mustangmike6996]

bench bleed the master cyl. do it the correct way with the bench bleed lines that feed from the master cyl housing back into to resivour. this is where most air bubbles stay... and are very hard to purge thru the entire line system

 

[Jimmys66]

When I first did the swap the brakes were a little mushy for the first inch or so but, had comparable effort to my non power drum brakes. The rubber lines I had on the back were new.

Each corner of the car was bleed at least 6 times after I swapped the rear lines and the brakes start applying pressure at the very top of the travel of the pedal.

Litteral all I did was change the rear lines to ss and bleed the snot out of it with some valvoline syn power synthetic fluid.

 

[BlwnGazkit]

Well then maybe you had an air bubble from the beginning that you've since removed... Sorry I'm not being very helpful, I just can't think of any reason for the symptons you've described.

 

[Jimmys66]

Me neither. Maybe getting rid of any extra air in the lines(and I know I had some)caused the pedal to feel stiffer like you said.

It's still usable but, I'm going to have to start working out again.

I know swapping to dot 5 silicone will make the pedal hard but, I wouldn't think I'd have any problems with the synthetic.

 

[BlwnGazkit]

Well you could always put an air bubble in there!! lol

 

[Jimmys66]

Well you could always put an air bubble in there!! lol

Thanks for the laugh. I guess I did like the brakes a little more "spungee".