Break Booster? - 69 Barracuda Mod-Top

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Dratsum

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Hi - I have no experience with MOPAR and I'm helping my girlfriend restore her 69 Barracuda Mod-Top that has been in storage for 4 years. Have a question about brakes.

The car runs really well - we changed the fluids, gas, battery, etc. But the Brakes are really soft, and the brake pedel is really high. There don't appear to be any leaks, so, we thought maybe we needed to replace the master cylinder. I know the 69's had a 'power brakes' option. Is that what the brake booster is? We don't appear to have one (see pic), but I considered buying a brake / booster combo to give her better braking response. Is the install for that pretty strait forward, or, is it a larger job?

Thanks / drats

IMG_5025.JPG
 
A booster is actually assist so the drivers pedal effort is decreased. It wouldn't change the capability of drum brakes. I'm going to guess that slant 6 car has 9 inch drums with a 3 inch wide shoe up front. You cant buy the OEM asbestos linings for them. The most agressive semi metallic linnings available would help but would also eat those drums that aren't easily replaced.
If this was my car and I wanted to keep it small bolt pattern and close to OEM as possible, I would invest in the optional K-H power disc brake option and 10 inch rear brakes common to V8 builds.
Like they say , "We are better off with one that wont go than one that wont stop".
Hope this helps
 
Thanks RedFish - I think it's discs in the front, drums in the back. She says the breaks weren't this soft before she stored it, and we had a mech look at it and he said the pads were good..

I forgot to mention this, but, when you pump them, they get tighter.

Ultimately I think we want to do a full disc conversion.. but in the short term, I just want it to stop :D
 
pumping is bad-- your system needs bled, might be a cylinder on its way out, Lawrence
 
If they got stiffer the more you pump them, then there is air/leak in the system. If they are discs in the front, the calipers might need to be rebuilt, or like abv said, leaky wheel cylinder for the drums. Chk all the lines over as well for leaks.
 
You just need to bleed the brakes. 9" drums get a bad rap from everyone. They aren't nearly as bad as everyone acts like they are. I've been daily driving on them for 10 years now without a problem. Bleed them, don't tailgate and you'll be fine.
 
Any recommendations on a Disc conversion kit? Is this one any good?

http://www.ebay.com/itm/WILWOOD-DIS...pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr

Do you have 9 inch drums or 10 inch drums. The link you have is for 10 inch drums and won't fit 9 inch unless you change the spindles. You will need additional parts that are not in this kit to complete the conversion.

You should also read the instructions before you buy any kit. Here is the one for the link your provided. [ame]http://www.southwestspeed.com/docs/WIL_140-11023Instructions.pdf[/ame]
 
I've driven on the 9 inch drum brakes too. I renewed everything about the brakes on that car shortly after i bought it. Still wouldn't stop well enough to suit me. Wife was even more displeased with that cars brakes. Thus, upgrading to 73 up pwer disc brakes was the very upgrade that car received. Yes it carried 2 spares for a long while.

I didn't mention any of this earlier for 2 reasons , I assumed 9 inch drums, Mine was nothing like a 69 Mod Top car. Good luck
 
I actually don't know if they are 10 or 9's... whatever was stock... has original brakes.
 
I actually don't know if they are 10 or 9's... whatever was stock... has original brakes.

Your car could have either and be totally stock. You will have to check if you are going to buy a kit because the 10 inch brakes were optional just like the disc brakes. In my opinion (for what it is worth) I would find and buy a set of the factory disc brakes for the car if you want to stay original equipment as wheels. If you want to go with the big bolt pattern so you will have a better selection of wheels then go with the 73 up parts like Redfish was talking about.
 
"X2" means he agrees that Wilwood is a good kit.

You must determine if 9 or 10" drums. You can pull a wheel and measure the drum OD. 9" drums are 9"ID and ~10.5"OD. Look at www.rockauto.com for parts and photos to learn more. You can also look for the "max ID" stamp on the drum, which would be something like "9.008 in D max" for 9" brakes. The spindles are different between 9" and 10" drum cars, so it does matter, and changing spindles isn't trivial.

If 9" drums, Scarebird makes an affordable bolt-on disk kit that uses Chevy and Toyota parts. For any disk kit, you will need at least 14" wheels and sometimes 15" to clear the calipers.

I don't think the much-discussed 73+ BBP disk conversion is a good option for you. It takes a skilled mechanic and raises other issues, such as changing the rear end or carry 2 spare tires.

You sure don't need rear disks. That is more of a show-off thing, and mostly for marketing in new cars today. Front brakes do 70% of the braking.

The 1969 factory K-H disk brakes are also not a good option for you, since you must change the spindles, as above. It would let you keep the SBP rear-end. A guy on FABO sells a complete setup occasionally, but ~$750 and getting future parts is hard.

Finally, I agree that 9" drums work fine. I had that with a manual MC on my 69 Dart for decades and it worked fine. Not too hard to skid the tires, which is the best you can do with any brakes. My wife drove that car for years and never complained and she is a cautious Asian lady driver. I did over-heat the brakes once on a gravel mountain road, where I had to brake too much on turns, but I also did that in my 65 Newport with its massive 11"x 3" front drums. Disks do cool off quicker, which is their main advantage, but of little concern in normal driving.

As far as the pedal sitting too high, that could be the wrong MC and push-rod, but more likely is the factory design for manual brakes. I can't say I remember from my 69 Dart. As far as "soft", that could be some air bubbles in the lines. Change the fluid (search "bleed brakes"), which you should do every 2 years unless you use DOT 5 (as I). It could also be because the factory maybe used a smaller piston in manual MC's, so you get more pressure for the same force, but more pedal travel. Check rockauto. They show a 1" MC for my 65 Dart for both manual and power. Not sure that is correct, plus 69 may be different anyway.

If you still want power brakes, which aren't needed for drums and many don't even use with disks, you can buy a new kit for ~$250 (search here) or be cheap like me and get the brackets and lever from an A-body and install a booster/MC from a newer car like the ~95 Breeze in my 65 Dart (see post). I didn't want the heavy cast-iron MC of the junkyard Dart I robbed.
 
Dratsum, did you know we had a special MODTOP gathering at Carlisle in July? I wish you had the car going then and were able to bring it!
Is your car in Julie's MODTOP registry?
 

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Thanks BillGrissom for all the info.

I had the break system checked again, turns out there WAS a leak at the FL drum. It's been repaired, and the system bled. Brakes work a lot better now. Very firm. The pedal is still sitting really high. It's probably 4-6" closer to the driver's seat than the gas pedal. You maybe correct that it's factory, I could just be use to driving newer cars. But going from the gas, to the brake, requires a pretty significant lift of the knee. We've compensated through left foot braking, which is probably ok. I wouldn't be surprised if the push-rod was the wrong type either... when we got the car it had a GM alternator in it, bolted on backwards... so there's no tellin.

Still considering replacing the MC at some point, and going to front discs.

BB-Dave - OH Man, we would love to do a Mod Top day! Will you do it again next year? We just signed up at http://www.mooresmopars.com/modregistry.html - is that Julie's? - Also, do you know where I can get a Mod Top quarter window sticker?

- Drats
 
Thanks BillGrissom for all the info.

I had the break system checked again, turns out there WAS a leak at the FL drum. It's been repaired, and the system bled. Brakes work a lot better now. Very firm. The pedal is still sitting really high. It's probably 4-6" closer to the driver's seat than the gas pedal. You maybe correct that it's factory, I could just be use to driving newer cars. But going from the gas, to the brake, requires a pretty significant lift of the knee. We've compensated through left foot braking, which is probably ok. I wouldn't be surprised if the push-rod was the wrong type either... when we got the car it had a GM alternator in it, bolted on backwards... so there's no tellin.

Still considering replacing the MC at some point, and going to front discs.

BB-Dave - OH Man, we would love to do a Mod Top day! Will you do it again next year? We just signed up at http://www.mooresmopars.com/modregistry.html - is that Julie's?

- Drats

The brake pedal on these cars set much higher than the pedals on modern cars. Left foot braking is horrible for the system if you keep you foot on the brake pedal because it will cause wear on the brake shoes, brake drums plus cause excessive heat on all the brake componets. Many of these parts are obsolete already and more are being discontinued all the time. The rear 10" brake drums have been near impossible to find for years.
 
BB-Dave - OH Man, we would love to do a Mod Top day! Will you do it again next year? We just signed up at http://www.mooresmopars.com/modregistry.html - is that Julie's? - Also, do you know where I can get a Mod Top quarter window sticker?

- Drats

The MODTOP gathering in July was likely a one time thing. I thought we would have had a lot more cars?
I don't know of anyone doing the MODTOP decals. I have thought about trying to have them done, but haven't yet.
Yes that is Julie's MODTOP registry....is your car a new one for her registry? My car is #29 Dave
 
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