No Brakes

lilred

lilred

New member
I have a 1973 Scout II with a 345. This is a recent purchase of mine that my son and I are going to attempt to rebuild together. This is a life long dream of him and I but we are running into a few complications. I am by no means a master mechanic, I learn as a go. If I take it apart I can probably put it back together again. I have got the motor up and running a firing on all cylinders but before being road worthy I am having some major braking issues. As in I don't have any brakes. We have replaced the master cylinder and brake booster but still do not have any brakes. I can not find a vacuum leak nor can I find leaking break fluid. Do you have any ideas of what this might be?
 
Ok, first question is do you have any pedal? As in does it stop before it hits the floor. If there is no pedal, has the master cylinder been bench bled?
 
I have bleed the master cylinder when I installed the new one. I only have petal when I press it all the way to the floor. I feel pressure on the pedal through the entire length but no stopping power is applied until it is all the way down.
 
But did you do it on the bench before installing it in the rig and hooking up the lines? Bench bleeding any new master cylinder is an essential first step. Then you install it, connect the lines and bleed each wheel cylinder until only fluid with no air bubbles exit the bleeders. You still have a good deal of air in your system which is accounting for the weak pedal. Either that, or one of your wheel cylinders has ruptured and isn't holding pressure...or your "new" mc is a pos out of the box, which is far from unheard of these days. Is it an a1 crapdone reman = junk, or a truly brand new item?
 
Yes I fully bled before hooking up any lines. I ordered the mc from xxxxxxx..crediable site I hope?:icon_question: trust does not mean that the part is still not bad out of the box. I am at the point were I would rather send it to someone and make sure it is right. Any suggestions? What does a resteration on a Scout II run (motor rebuild, carb., brakes, etc?) I live in oklahoma any good Scout guys around here? I want on the road :icon_evil:
 
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If I understand you correctly this unit was not bench bled prior to bolting it to the vehicle. Scoutboy is trying to point out that if you didn't properly bench bleed that May be the problem. Bolting the unit in and then bleeding before hooking up the lines is not the same as bench bleeding.
 
This was bled before hooking up any lines. Good flow of dot 3 through front and back of master cyclinder before any lines were hooked up.
 
I'd start the bleeding process over by starting at the m/c and cracking first the fitting near the fire wall and then the further one to see if you get some air. Then do the normal bleed from the farthest point to the nearest and see if you get some pedal. It sounds like there is air in the system.

Did the system function properly before? And what was the failure mode?
 
lilred said:
yes I fully bled before hooking up any lines. I ordered the mc from xxxxxxx..crediable site I hope?:icon_question: trust does not mean that the part is still not bad out of the box.
the vendor didn't make the part, they just sold it to you. Do you recall the brand/label on the box and whether it was brand new or a re-manufactured item? I edited their name out because the vendor who owns this forum naturally frowns on references to competing vendors. IHPA offers a great many IH specific parts including master cylinders.
I am at the point were I would rather send it to someone and make sure it is right. Any suggestions? What does a resteration on a Scout II run (motor rebuild, carb., brakes, etc?) I live in oklahoma any good Scout guys around here? I want on the road :icon_evil:
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any time you hire out restoration and engine work, you're looking at thousands of dollars to get it done right. Not just a couple either. That goes for pretty much any vehicle. IHPA also offers this service, but you're a long way from norcal.
lilred said:
this was bled before hooking up any lines. Good flow of dot 3 through front and back of master cyclinder before any lines were hooked up.
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the quality of the help you receive on this or any tech forum is directly tied to the information you choose to offer. You're the man on the scene. The rest of us are thousands of miles away trying to cyber-wrench through our monitors. Details and specifics matter. You May think we're beating a dead horse, but vague descriptions and evasive answers just don't get it done. So next question. After you bled the mc and connected the brake lines, what did you do next?
 
Thanks for all the great advice. I will start the bleeding over again when the sun comes up with suggest method.

And the problem that I had before the m/c and booster was exactly what I am experiencing now. That is what makes me think the problem is else were.
 
It could very well be elsewhere. Since this is a '73 model year, in original configuration it would have drum brakes front and rear. Each drum brake will have a slave or wheel cylinder that applies force to the brake shoes in response to exerted hydraulic pressure from your foot pressing on the brake pedal. A rupture or leak at any wheel cylinder will result in lost pedal pressure. Low fluid levels observed in the mc after a short time also indicates a fluid leak in the system. The front reservoir supplies fluid to the rear brakes, while the rear res handles the front wheels. So if you've noticed one or both of the reservoirs needing to be topped off on a regular basis, that means you have a fluid leak. There will also be obvious signs of a leak on the brake backing plate of any wheel that has a failed wheel cylinder. If you have not had all the wheels and drums off for an inspection, now would be a fantastic time to get after that.
 
An added note on great advice so far. I just had a 74 Scout II come to me on a flat bed due to no brakes. Originally 74 and older came with drums on all four corners. Turns out that during the changing of hands through several previous owners some one swapped out front axle and installed a Dana 44 with rotors up front. The booster was wrong for what it was being used for. Plus the m/c was leaking. I replaced them with proper parts and now there's brakes

basically, if your axles have been swapped out and/or disc brakes were added in your Scout's life time, then make sure you have the correct m/c and booster. Or you will end up with no brakes
 
Kimball, your point is well made regarding a potential front axle swap and possible incongruity of parts. We'll have to wait for an update from the op regarding what brakes he has on his front axle. Just a nit picky fact check for ya though...there are plenty of '74 sii's that came with disc brake d44 front axles factory installed. I have one. '74 was a transition year for front axles in the scouts. There are known cases of factory disc brake d30 axles, and even a few drum brake d44 fronts out there. Weird things happen when old stock is being phased out at the same time new stock is being phased in. That's just how IH rolled. Some major changes just weren't perfectly synchronized with the new model year launch. Ihc was the honey badger of the automotive world. Honey badger don't care.
 
Thank you for the memory recall trever. I had a brain fart and forgot to mention that the 74 was the transition year. I too, have a 74 among my own personal fleet. The one I barrel rolled last year. It came originally stock with a Dana 30 with disc brakes up front.
 
I have a 73 as well with a swapped in 74 front with discs. I had a similar problem to yours in that I felt resistance the entire range of the pedal but would only stop when I hit the floor. For me the issue was the rod from the pedal to booster was not long enough after the swap and I had to make a new one out of some bar stock. If you are confident on the bleeding I would look at the range of motion, the new rod I made was only 1/4" longer but was the difference of working or non working brakes.
 
Easy now. Until otherwise informed, we still have to assume that this is a drums all the way around setup. The op is a newbie. It takes a trained eye to know what to look for when it comes to making proper id on this shit. Lets everybody exercise some patience here until we know for sure what we're dealing with. Op...if you don't know what you're looking at...please, please, please take some pics and post them so that those of us who've been in the rodeo awhile can look and identify your equipment.
 
If lilred is unsure about what parts are correct for the current set up, then posting a couple photos of the brake booster and master cylinder and front axle that includes the type of brakes. Untill we get some more info, I'm kinda of on the mind set that the brakes just May have been swapped to disc during the Scout's life time and the booster was not changed to compensate. The little push rod from the booster, May or May not be the culprit. Again, we won't know untill more info is provided
 
Just as an fyi, on my son's '74 Scout II, we swapped the d30/disc front and d44/drum rear axles for waggy d44/disc front and izuzu d44/disc rear. Replaced the mc with rebuilt stock, and put in a new proportioning valve we got from Jeff. Gotta tell ya, that critter will stop!
 
I was just tossing out something to look for and by no means claiming that it was the issue. I spent a couple of hours checking things out that I knew we're correct and it was very frustrating. Pedal travel is extremely important to look at in any brake swap as it can lead to several problems and it can mask its self as other issues very easily. Again it May or May not be at all part of the issue but it takes only a few minutes to check as where rebleeding the system generally takes long...
 
We were told with discs on all four, steve would need to go to something like the booster/mc out of a vette or some such, as the stock m/c wouldn't put out enough. Seems that May be an intardnet fable now that we are running the stock m/c and four wheel discs. Just shows to go ya May not want to believe what you see on some forums. I'm sticking to what's posted here.
 
Thanks you guys are great

sorry, I have not had a chance to do any maintenance this weekend. I am on the local fire dept as well and it is has been a slightly busy weekend.

Yes the previous owner has made a swap to a dayna 44, I will check rod travel and if mc is correct. I did not think about any of that
 
lilred said:
thanks you guys are great

sorry, I have not had a chance to do any maintenance this weekend. I am on the local fire dept as well and it is has been a slightly busy weekend.

Yes the previous owner has made a swap to a dayna 44, I will check rod travel and if mc is correct. I did not think about any of that
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No worries. I thought about becoming a firefighter when I was younger.

With disc or drums?

What type of booster do ya have? I keep refering to it due to the fact I just replaced a booster in 74 Scout, for another member here in the forum, that had the wrong one for the Dana 44 with disc that a previous owner installed. The wrong booster was the cause of the no brakes. If you're not sure if the booster is correct, post up a photo of it. The booster is what the master cylinder gets bolted too. Worse case scenerio, and I could be wrong, a booster May not have been installed from the get go. Meaning manual brakes from the beginning. Doubt it though.
 
Another simple possibility is the adjustment of his drum brakes. If they are out of adjustment, it will also result in a pedal going almost to the floor. With new brakes, there should be drag felt when turning the wheel by hand in either direction.
Steve
I've never worked on IH brakes before but I'm sure its the same for all drum brakes.
 
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