Tfreddy45,
(Apologies in advance for the length of this "epistle".)
Perhaps like you, my wife and I have an early 2000's SMB (we're 2nd owners) with a GM/GMC K30-type Dana 60 front axle whose brakes were quite (Ahem!) "underwhelming" when we got her. Like many used SMB's, the brakes were just one of the many things that seemed to need repair, upgrade, or just "personalization" to make her truly "ours". Full disclosure: although my name is jointly on the title and registration with hers, it's absolutely my wife's van. I just carry the repair and upgrade responsibilities.
One of the "Silver Kitten's" other problems besides "iffy" braking was the well-known and much-dreaded "Death Wobble" during braking, which has since been fixed. However, in the course of fixing the S.K.'s Death Wobble, I had to do a lot of maximum-braking-effort stops from 55-65 MPH for diagnostic and testing purposes. After 12-20 hard stops, I noticed that the braking was now much more effective, i.e. I was getting a lot more "Whoa! power" in return for much less pressure on the brake pedal.
So just in case your brakes are "glazed" like ours apparently were (the previous owner towed a large boat with his SMB), I would humbly suggest that you find a quiet country road where you can do a series of hard stops (12 or more) from 55 MPH+, and see if that doesn't improve your braking situation. It's one helluva lot cheaper than a brake upgrade, and might be all that you need to do.
But before this money-saving turn of events happened with our S.K., I too was looking for brake upgrades. There is considerable expertise on this subject among the members of this forum, both past and present, that can most-easily be found using Google instead of the search tool on this forum, by using sportsmobileforum.com followed by whatever you're searching for as your search key. However, I would recommend that you start with this link:
https://www.sportsmobileforum.com/fo...-10808-20.html
BoyWonder's herculean efforts aside, there are also other external brake upgrade resources for GM/GMC Dana 60 axles that I considered, including this one, which allows adaptation of the Ram 3500 brakes onto the GM Dana 60 kingpin axle:
https://torqmotorsports.com/product/...rake-brackets/
However, in looking at the various brake upgrade options available for our SMB, I have so far been unable to convince myself that they offered any "huge" braking advantage that would improve "panic stops", which is what I was looking for. On the other hand, the potential benefits that I *did* see in the various upgrades included:
1) Possibly increased brake pad area. I would assume that this is real, but I haven't gone down to the auto parts store to look at the surface area of Ram 3500 pads vs. GM K30 pads.
2) Slightly increased braking torque (braking effectiveness) resulting from increased rotor diameter, due to the caliper and pads applying the friction to the brake rotor at a point slightly farther away from the wheel's axis of rotation. This could possibly provide a significant amount of mechanical advantage in the braking system, and I would suggest that you review the comments from other SMB forum members about their experiences.
3) Reduced brake "fade" on long downhill stretches due to increased thermal mass of the brake rotor: Having larger brake rotors made out of more metal increases the thermal mass of the rotor, and may also improve cooling via increased internal/external rotor surface area. Greater mass and greater surface area can both help to slow or limit the temperature rise of the rotor in any given braking situation.
4) Improved brake pressure "even-ness" across the surface of the brake pad: The stock GM brake calipers on the Quigley-installed Dana 60 axle have a *single* 85.5mm diameter piston, which relies on the stiffness of the steel backing plate to distribute the pressure from the piston across the entire surface of the brake pad on the piston side. In contrast, the caliper assembly from the Ram 3500 trucks has two 59.9 mm diameter pistons, which may spread the clamping force of the caliper assembly more evenly across the surface of the brake pad on the piston side. However, in terms of mechanical advantage in the braking system, the piston area of the GM caliper comes out to about 5,741 square millimeters, and the total piston area of the Ram caliper's two pistons comes out to about 5,634 square millimeters (I think), if I did my math correctly. This means that the GM calipers that we/you may already have would actually have a slight (1.9%) mechanical advantage in terms of caliper clamping force per unit of force applied to the brake pedal. This is a very small difference that I suspect would be very hard to notice. But the real takeaway here is that changing from the GM to Ram caliper assembly probably wouldn't provide any noticeable increase in mechanical advantage that couldn't be completely "swamped" by differences between your old brake pads and the new ones that you would have to install as part of the rotor/caliper upgrade.
If I upgraded the S.K.'s brakes with larger rotors and new calipers, this would similarly force me to swap out brake pads, and I might find something better than the unknown pads that we're currently using, which the previous owner installed. (We didn't get all of the receipts and records that we were promised when we bought our used SMB, so our current brake pads are an unknown.) But then, I could try different brands/types of brake pads right now, and for a whole lot less cash than doing a full-blown brake system upgrade. I am viewing this option as a possible "easy upgrade" to the S.K.'s brakes - above and beyond the apparently effective "glaze removal" that I have already done.
Really, the next thing on the S.K.'s brakes that I am planning to look at is the vacuum pump and brake booster system for the 7.3L PowerStroke Diesel engine, just to make sure that I don't have any vacuum leaks or a worn-out vacuum pump that might be limiting the "help" that the brake booster provides. (Accumulating 140,000 miles does wear a bit on rubber and other things.)
Good luck to you in your journey towards better braking, and please feel free to reply in this forum or P.M. me if you have any questions about my experiences with this!
Timerider
watchtower, white whale, land yacht, big pig...
Linear Mode
