I havve an 88 v2500 with a d60 in the front and a drum sf14bolt out back. My brakes are underwhelming even with all new parts. Im guessing a different master is needed since i upgraded the front. Is it as simple as getting one from a k30? Or is there a better option? Not looking to go hydro boost yet.
CK5
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Master cylinder selection
- Thread starter kbclamper
- Start date
First is your rear adjusted properly?
It makes a big difference.
As for master, yeah there's a k30 booster that would do better but the big tires will overwhelm any brakes made stock for those years.
I don't know if it's an easy upgrade but ford d60 has dual pistons, should be an upgrade
Do you have hydro boost? My 3/4 ton would detach retinas when it was up and running.
He did say he's not ready to go hydraboost
Im running a P30 master
Did you replace the calipers? Where did you get them and what brand? Are the caliper slides clean so it can slide properly?
Since you mentioned that the brakes were better with the 10B calipers try and help paint us a better picture of the situation - has this ride set up for a long while since last driven or is this a “it worked great on Friday and over the weekend the swap was done and now the brakes are questionable” type of thing ?
What’s the age and condition of the front rubber brake hoses - they can and will deteriorate from the inside and limit pressure or even hold pressure ?
While bleeding them what was the fluid flow like - a twelve year old type pressure while peeing over a fence contest or more like an old man with prostate problems gett’n his toes wet ?
And the questions KENNYW asked are very valid and most likely the culprit - calipers not sliding easily or pistons not moving easily will cause the issues you are describing.
Could it be that the calipers are “new” as in not ever used but have aged by sitting up in storage and condensation has effected the internals ?
Did you use brake caliper grease on the sliders ?
What’s the age and condition of the front rubber brake hoses - they can and will deteriorate from the inside and limit pressure or even hold pressure ?
While bleeding them what was the fluid flow like - a twelve year old type pressure while peeing over a fence contest or more like an old man with prostate problems gett’n his toes wet ?
And the questions KENNYW asked are very valid and most likely the culprit - calipers not sliding easily or pistons not moving easily will cause the issues you are describing.
Could it be that the calipers are “new” as in not ever used but have aged by sitting up in storage and condensation has effected the internals ?
Did you use brake caliper grease on the sliders ?
Ill try to answer everything.
Everything is new. I had the axle fully rebuilt before i installed it. Everything works now i just feel like it should be better. I had a firmer pedal with less travel with the 10 bolt which makes me lean towards a different master being needed for the bigger calipers. The pedal is the same now as when the axle went in.
Everything is new. I had the axle fully rebuilt before i installed it. Everything works now i just feel like it should be better. I had a firmer pedal with less travel with the 10 bolt which makes me lean towards a different master being needed for the bigger calipers. The pedal is the same now as when the axle went in.
The bigger master for bigger calipers assumption may not be correct. I have a 1990 K5, D60 front with stock reman calipers and a 2002 AAM10.5 rear with stock reman calipers (which are huge). Running a stock K5 master, vacuum booster. Locks the tires up fine and the balance is good too. I added a Willwood proportioning valve to the rear because I was expecting to need to dial the brakes back a bit. I have never needed to adjust the rear. 37" Toyos.
I have never read here that there is a single recipe for great brakes when you start swapping parts. I was pretty worried about dialing in my truck when I started changing axles. Some guys go through all sorts of masters, change calipers, and still never love their setups. Others seem to just work fine with random parts. I may have got lucky, but I expect its because I am disc/disc of similar size, 1 ton stuff.
I know this isn't very helpful advise, but you are going to have to do some research here about trucks with a similar axle setup and probably try a couple setups until you are happy. The K30 master may solve it but with stock 2500 rear SF drums its hard to guess what the results may be.
I have never read here that there is a single recipe for great brakes when you start swapping parts. I was pretty worried about dialing in my truck when I started changing axles. Some guys go through all sorts of masters, change calipers, and still never love their setups. Others seem to just work fine with random parts. I may have got lucky, but I expect its because I am disc/disc of similar size, 1 ton stuff.
I know this isn't very helpful advise, but you are going to have to do some research here about trucks with a similar axle setup and probably try a couple setups until you are happy. The K30 master may solve it but with stock 2500 rear SF drums its hard to guess what the results may be.
When you increase the diameter of the caliper piston, your foot travels further to engage it, but you get more stopping force or less pedal effort, depending on your definition. If you get a larger bore master cylinder, the opposite happens. Pedal travel is reduced, but also stopping power. The ratio of those diameters is comparable to gear reduction from different tooth counts. I believe the rotor diameter of an 8-lug 10-bolt is similar to a D60 rotor.
Anytime there is any air trapped somewhere the brakes will feel like doo. Please describe how you have adjusted the rear brakes and how the system was bled.
Anytime there is any air trapped somewhere the brakes will feel like doo. Please describe how you have adjusted the rear brakes and how the system was bled.
Just found this looking for some brake stuff and don't see resolution and do see some picture perfect observations. The bigger calipers of the D60 will take more fluid to move compared to the 1/2 or 3/4T calipers. So the pedal will travel more, just like you found. It'll actually make good pressure since it's a small bore master but it will need to travel more to do the job so the brakes will feel softer or "spongy-er". Some might call that easier to modulate. I had exactly the same experience on multiple rigs: long pedal travel with 1-ton axles and 1/2T masters. In general, I'm fine with it.
The 1/2T will usually have a 1 1/8" or 1 3/16" master. A K30 has a 1 5/16" master so you can see it's way bigger. But, the K30 master comes only with hydroboost to provide the assist to make that giant master work. You don't want to put that master on a vacuum booster.
In the end, the pedal travel could be considered a feature and obviously a lot of guys are fine with it. You might not be because people are different. The "proper" fix is hydroboost and a K30 master. At that point you'll have a firm pedal with lots of power on tap but some might consider it twitchy. It can take a minute to get used to compared to softer pedal systems.
and to keep the record straight, a K30 rotor is way bigger than the 3/4T stuff. Like 1.5" bigger. The K30 really has good brakes. It's become fashionable to put bigger brakes on D60s and in some cases (high gvw tow rig being one of them) it makes sense, but for most people, the the stock K30 stuff is just fine.
The 1/2T will usually have a 1 1/8" or 1 3/16" master. A K30 has a 1 5/16" master so you can see it's way bigger. But, the K30 master comes only with hydroboost to provide the assist to make that giant master work. You don't want to put that master on a vacuum booster.
In the end, the pedal travel could be considered a feature and obviously a lot of guys are fine with it. You might not be because people are different. The "proper" fix is hydroboost and a K30 master. At that point you'll have a firm pedal with lots of power on tap but some might consider it twitchy. It can take a minute to get used to compared to softer pedal systems.
and to keep the record straight, a K30 rotor is way bigger than the 3/4T stuff. Like 1.5" bigger. The K30 really has good brakes. It's become fashionable to put bigger brakes on D60s and in some cases (high gvw tow rig being one of them) it makes sense, but for most people, the the stock K30 stuff is just fine.
