Brake upgrades?

[Morris]

I have never been happy with the brakes on my car and after I nearly wrapped under the axle of a truck this past weekend, I am motivated to explore improving them. Can you guys help me understand a few things?

• Can anyone point me to a write up on the MGB Caliper/Spitfire Rotor upgrade?
• Would there be any advantage to converting to a single circuit system with a remote servo? My understanding of the dual circuit is that it does not provide any additional safety. If one circuit fails, you have no brakes, correct? So is there a great advantage to keeping the dual circuit system? Doesn't a proportioning valve do basically the same thing as the dual circuit master?
• Have you seen any DIY rear disc mods? Do you know of an affordable rear disk kit?
• Is there any advantage to changing my master bore?
• Do you have any advice for improving my braking performance?

Thanks in advance!

 

[smaceng]

Morris, I could not find out the year and model of the car you drive....so here are some vague answers:
-Do not have any info on the MGB upgrade
-I assume you have front disc brakes? Yes, a double circuit does provide more safety if one end of the car loses fluid. It in itself does not provide any additional stopping power. I've never heard or seen a remote servo. A proportioning valve is commonly used on a disk brake front/drum rear car. It reduces the tendency for the rear brakes to lock up in a panic stop. Probably does not make the car stop much quicker, but does reduce the chance of it swapping ends.
-there are disc brake mods, but I would concentrate on the fronts as they do most of the work
-make sure all the brake parts are in good working order, including the rears. You could go to premium pads. then think about upgrades.
-If you do a panic stop, do you get all four wheels to lay down rubber? If so, can't get much better than that!
cheers, Scott in CA

 

[Morris]

Thanks Scott. In the panic stop in question, I locked the front, but they seem to lock to quick and easy. This could be my tires which I also am not happy with. It did not seem like I got much from the rears. With the fronts locked I was faced with skidding into the truck in front of me. Fortunately I was able to jump a lane. But probably would have been fine pumping the brakes. I shudder to think what would have happened had my wife been driving. Perhaps I have become too accustomed to anti-lock brakes.

 

[Morris]

Oh... and my car is a '79.

 

[drooartz]

If your fronts locked, going with a more powerful front brake setup won't help. Start with the tires -- sticker tires will give better adhesion and better stopping power before they are overwhelmed and lock up. You will have to unlearn your ABS reflexes as well, can't stomp-and-steer like you can with ABS.

Spridget brakes in good condition can lock the front and rears. Also, look into some high quality front pads (like EBC Greenstuff as an example).

 

[smaceng]

Check the back brakes. Sometimes they are hard to adjust correctly so that the adjustment is one or two clicks from serious drag on the shoes. Also make sure the parking brake releases completely. check the front and rear brakes to make sure the disks, shoes and pads are clean without any oil or brake fluid.

 

[Morris]

I replaced the rear wheel cylinders a few weeks ago and replaced the front bearings before that. I finished with a system flush and bleed front and back. Everything got checked and cleaned during that process, so unless I have new leaks to deal with everything should be clean. I will double check my rear adjustment. I am pretty sure I set them up the way you suggest, but I could be wrong. Perhaps a few miles, then re-adjustment are required to get everything right.

Drew, your stomp and steer remark is dead on the money. A fraction of a second after stomping and locking I steered for the next lane... then I pumped. I fairly jumped into the next lane. It 'twere pretty embarrassing.

Of course all this could have been avoided had I been watching the rear bumper of the truck instead of the beautiful river I was crossing at the time. My wife's attention span is far greater than mine so maybe there is nothing to worry about.

 

[Gerard]

I have never been happy with the brakes on my car and after I nearly wrapped under the axle of a truck this past weekend, I am motivated to explore improving them. Can you guys help me understand a few things?

• Can anyone point me to a write up on the MGB Caliper/Spitfire Rotor upgrade?
• Would there be any advantage to converting to a single circuit system with a remote servo? My understanding of the dual circuit is that it does not provide any additional safety. If one circuit fails, you have no brakes, correct? So is there a great advantage to keeping the dual circuit system? Doesn't a proportioning valve do basically the same thing as the dual circuit master?
• Have you seen any DIY rear disc mods? Do you know of an affordable rear disk kit?
• Is there any advantage to changing my master bore?
• Do you have any advice for improving my braking performance?

Thanks in advance!

Not only do I second Drew's remarks regarding a bigger brake kit, but the MGB/Spitfire setup is not that big of an improvement for the street, and is a huge pain to fit, and doesn't fit that easily or well. There are other front disc brake upgrades that are better.

The dual circuit issue has been covered. It is not the same as a proportioning valve.

There are rear disc brake upgrade list sold, but they start around $1500.

Changing the bore will not improve braking, only change how much pedal effort is required. The same goes for a servo. It will not improve braking, just reduce pedal force required.

I think having good and true rotors, properly adjusted rear brakes, better quality pads and shoes, as well as better condition, appropriate tires, is where to start. I think keeping a good distance from modern vehicles with vastly better performing brakes will go a long way too.

 

[Guest]

Got all new hoses too?

I'm w/ Gerald and Drew on everything else. I can lock mine, right front first ALWAYS!

 

[smaceng]

BTW here is info on the big brake conversion using MGB parts:
https://www.minimania.com/part/HUF175/Big-Disc-Brake-Adapter-Kit-pair-Sprite--Midget

 

[Morris]

In trying to understand this better I stumbled on this page: https://www.tegger.com/hondafaq/mastercylinderreplace/index.html

I now understand why dual circuits drop to the floor when one circuit is open... and why this does not mean you will lose both front and back brakes in an emergency.

I will order some new pads and shoes and see if that fixes my complaints. The tires I have are gonna stay on the car until I get around to buying new wheels. They are new and I am too cheap to throw them out before then.

Thanks guys.

 

[Gerard]

BTW here is info on the big brake conversion using MGB parts:
https://www.minimania.com/part/HUF175/Big-Disc-Brake-Adapter-Kit-pair-Sprite--Midget

That's the kit I used. It's very incomplete, and doesn't fit without a lot of grinding to various components, including the new rotors and calipers. They also couldn't answer my questions about what else was needed and a variety of other technical things... and couldn't be bothered to find out. I've installed many disc brake upgrade kits on other cars, and I would never consider installing this one ever again.

 

[Gerard]

Got all new hoses too?

I'm w/ Gerald and Drew on everything else. I can lock mine, right front first ALWAYS!

Who's Gerald?

 

[Morris]

:eagerness:

 

[BuggerAll]

:eagerness:

I installed the Spit/MGB "upgrade" on my hot street BE and am about to take it off. No measureable improvement, in my opinion. On my SCCA Midget I have the stock calipers and rotors up front, per the rules. With Hawk Blue pads, and a tandem M/cyl set-up (5/8" cyl on front, 3/4" for rear), plus the winner's circle rear disk conversion working through an adjustable proportioning valve, this car stops very, very well. Also, those Spit rotors are no longer being made by Brembo or other reputable manufacturers.

 

[64rocksprite]

Morris - I think you're on the right track with tires, the 'grippier' they are..the better you stop (resist sliding longer). If you can lock them up, last thing available is tires (and don't forget...following distance!!):smile-new: provided the rears are doing their part..

 

[aeronca65t]

My racer has completely stock brakes.
Rotors are Brembo, but just normal ones like Moss sells.
I tried running the racing pads, but I found it was too hard to get them hot enough.

The only issue with rear brakes is keeping oil off them from the goofy hub seal. The stock linings work OK.

You already know the real solution:

Stop looking at those "beautiful rivers"! :friendly_wink:

(we're all guessing that "beautiful river" is code for something else) LOL!

 

[Morris]

Ha! Nial, there are a lot of "beautiful rivers" here in Austin and I am sure they cause more than a few of the 1000s of wrecks that happen here everyday. But in this case I was looking at the actual Colorado River.

 

[Bayless]

Right

 

[Morris]

What do you guys think about using this master?

https://www.ebay.com/itm/EMPI-16-95...CYLINDER-/310153566369?_trksid=p2054897.l4275

It's dirt cheap. The flange is oriented differently, but the remote reservoir aspect makes it a bit of a non issue. Nothing time with my drill press and grinder can't fix. The bore is just slightly smaller than stock, so it should give a bit more umph.