brake pedal travel
 

About a year ago I installed new dual res MC ,new brake lines, front discs on front and new shoes and cylinders on rear. Pressure bled system and had brakes. Put the cab on a few weeks ago and yesterday install a remote reservoir on the firewall. Hooked up the pedal and I have 4 inches of pedal travel before the the pushrod makes contact with the piston. I have the pushrod fully extended. I looks like I need a longer pushrod. Anyone run into this? I'm going to go get some more brake fluid and rebleed the entire system but I dont think thats it. I dont think it bled down ,I just never had the cab and pedal on before and didnt concern myself with the travel.

Re: brake pedal travel
 

Read the third post on this discussion. https://67-72chevytrucks.com/vboard/...d.php?t=498293

Should help you determine if you have a mix of short/ long or the proper parts.

Re: brake pedal travel
 

It looks like I have a deep bore with a short pushrod. I have mechanical brakes. I wonder why they gave me the wrong pushrod. I bought everything from them. I cant find the pushrod adaptor on their site . Do you have a part #

Re: brake pedal travel
 

Finding just pushrods is not easy. and when you get boosters they often do not come with them because the theory is you use the one you are replacing.
If they gave you the wrong one in a KIT then I would work with the vendor to get it corrected.

Since I was a budget build and cobbled parts together for one of my truck.
I just went to pull a part yard. found a booster with longer rod. Just took the rod for I think a dollar.

Then just ground the end to the exact length I wanted.
I did it on the bench with small adjustments each time till i got it where it was spot on for my master and booster. Then smoothed the end to almost a polish. rounded just like the rod that was missing.

Re: brake pedal travel
 

https://www.classicperform.com/Store.../5559MMK-2.htm I have this one. It looks like the pushrod is just a threaded rod on a heim joint

Re: brake pedal travel
 

ah you have no booster. I was thinking internal push rod not external.


do a search for universal adjustable pushrods there are a few out there that will work for your application and allow you to make adjustments as needed.

Re: brake pedal travel
 

here is what I mean if you get that threaded size off your existing you can find ones that match that you can cut to fit or maybe get lucky with exact size

Re: brake pedal travel
 

Thanks that will work. All I really need is a piece of threaded rod I'm wondering why the didnt provide the correct pushrod when I bought everything. I cant be the only person who this has happened to

Re: brake pedal travel
 

No Idea on them sending the wrong part but stuff happens.

When you are under the truck you want the pushrod to just barely move before you feel it contact the piston. That is reaching up with one hand and moving the pedal while watching the rod move and make contact. You should be able to pull against the return spring with your fingers a few inches up the pedal arm and feel it make contact.

Re: brake pedal travel
 

before you start make sure your pedal has a travel stopper so the pedal stops at the same place every time when the pedal is released. usually this is a rubber block on the pedal arm that hits the firewall on the engine side of things. whatever your system looks like just make sure there is a definate stopper on the pedal that will stop the pedal at the same place each time, otherwise your pushrod adjustment will change each time the pedal is released. ensure the pedal linkage is aso free of worn parts that allow slop in the linkage etc, there are no parts binding on anything, the return spring is strong enough to bring the pedal back to the top of it's travel quickly every time. also, since the cab is now part of the pedal stopper, ensure the cab mounting system is also in good shape and tight
once you have that set and all is good then adjust the pushrod so when the pedal is let go and it is against the travel stopper you have a definate pushrod freeplay at the master cylinder according to the shop manual spec, or at least some amount of free play

Re: brake pedal travel
 

I have fabbed up pushrods for different custom builds by using a grade 8 bolt of appropriate length with the head of the bolt cut off and then, once the length is determined to be close enough so adjustment can be made with the threads, the cut off end of the bolt gets a rounded and smoothed end ground in. I'm not a fan of the threaded rod idea because the rod is soft and it has threads all the way down so the effective diameter is actually smaller. I think most pushrods use a fine thread and possibly that is because the threads are not a deeply cut into the round stock of the bar they use for the pushrod, so less diameter change from the diamter of the rod to the root of the thread. if you get what I mean.

Re: brake pedal travel
 

I bought one online . Arrives tomorrow. Thanks

Re: brake pedal travel
 

I bent a piece of threaded rod (NOT all thread) on my 48 because it wasn't strong enough for the length it hsd to be. I built a much stouter pushrod Using a piece of hollow Ford steering shaft that I had saved years earlier. They had the center open to run the horn wire down through. I'd think tai if it is missing the pedal will be too high too.

47/59 trucks need a pedal stop on the pedal shaft under the floor as dsraven said. #5 in this LMC image