rear drums to disc brakes

[glfredrick]

Note that if you are opening the brake lines to do a swap, you should bleed the entire system. All it takes is for an air bubble to work its way into the system to have very weak brakes. By now, the brake fluid is due for a change anyway, as it attracts water and creates bigger problems (like weak brakes).

Bleeding (and bench bleeding a MC) isn't that difficult. You just fill it with fluid, put a couple short stubs of hose from the fittings back into the cylinder and slowly stroke the piston in and out about 10 times. That's standard for any MC work.

Bleeding the rest of the system is also a no-brainer. Just do the rear (tire farthest away from the MC) first, then the other side rear, then the passenger front, and finally the driver's front. It only takes a couple of minutes, and you'll pump out all the old brake fluid in the process.

Not sure why people are so frightened about bleeding brakes that they avoid it at any cost, but that is about half of what makes a brake job a good and successful job versus a death trap!

Good article here:
http://www.popularmechanics.com/automotive/how_to/4213448.html

 

[jd4242]

yea when I replaced everything in the rear last time I flushed the whole system and went to synthetic brake fluid,don't know if that was bad for it or if didnt hurt

 

[glfredrick]

yea when I replaced everything in the rear last time I flushed the whole system and went to synthetic brake fluid,don't know if that was bad for it or if didnt hurt

Sometimes brake fluid is funny stuff. Watch how you blend it! Not all varieties are suitable for mixing. It can wipe out the seals.

Generally in a DOT 3 system (Explorers) re-using a good grade of the same is best. No need for synthetic in this instance (though I am a HUGE fan of synthetic).

Here is one of the best articles I've seen on the subject.

Brake FluidsOZbrick:

by Kenneth Streeter, with input from Mike Burdick, Shane Ingate, Chris Kantarjiev, a "Skinned Knuckles" article, and various other sources

The discussion of whether to use DOT3, DOT4, DOT5, or the new DOT5.1 brake fluids is a common topic. The information provided herein should
help you to decide which of these brake fluids are best for you and your car. I would point out that I am not an "expert" on the topic, but have collected the experiences of many other enthusiasts, as well as opinions of professional auto restorers. I have tempered my findings with my own experiences and
opinions.

I would also take this opportunity to point out that the type of brake fluid used in your car is far less important, from a safety standpoint, than a properly functioning braking system. If you are working on your own brakes, be extremely careful, don't skimp on poor components, and bleed the brake system very carefully and thoroughly.
DOT3
DOT3 brake fluid is the "conventional" brake fluid used in most vehicles. One of the most familiar brands is "Prestone."
Advantages:

• DOT3 fluid is inexpensive, and available at most gas stations, department stores, and any auto parts store.

Disadvantages:

• DOT3 will damage natural rubber brake seals and should not be used in any car suspected of having natural rubber seals.
• DOT3 fluid eats paint!
• DOT3 fluid absorbs water very readily. (This is often referred to as being hydroscopic.) As such, once a container of DOT3 has been opened, it should not be stored for periods much longer than a week before use.
• Since DOT3 fluid absorbs water, any moisture absorbed by the fluid can encourage corrosion in the brake lines and cylinders.

DOT4
DOT4 brake fluid is the brake fluid suggested for use in late model cars. The most familiar brand is "Castrol GT-LMA"
Advantages:

• DOT4 fluid is available at most auto parts stores, and at some (but not all) gas stations or department stores.
• DOT4 fluid does not absorb water as readily as DOT3 fluid.
• DOT4 fluid has a higher boiling point than DOT3 fluid, making it more suitable for high performance applications where the brake systems are expected to get hot.

Disadvantages:

• DOT4 fluid eats paint! Small leaks around the master cylinder will eventually dissolve away the paint on your bodywork in the general vicinity of the leak, and then give rust a chance to attack the body of your car!
• DOT4 fluid is generally about 50% more expensive than DOT3 fluid.
• Since DOT4 fluid still absorbs some water, any moisture absorbed by the fluid can encourage corrosion in the brake lines and cylinders.

DOT5
DOT5 brake fluid is also known as "silicone" brake fluid.
Advantages:

• DOT5 doesn't eat paint.
• DOT5 does not absorb water and may be useful where water absorption is a problem.
• DOT5 is compatible with all rubber formulations. (See more on this under disadvantages, below.)

Disadvantages:

• DOT5 does NOT mix with DOT3 or DOT4. Most reported problems with DOT5 are probably due to some degree of mixing with other fluid types. The best way to convert to DOT5 is to totally rebuild the hydraulic system.
• Reports of DOT5 causing premature failure of rubber brake parts were more common with early DOT5 formulations. This is thought to be due to improper addition of swelling agents and has been fixed in recent formulations.
• Since DOT5 does not absorb water, any moisture in the hydraulic system will "puddle" in one place. This can cause localized corrosion in the hydraulics.
• Careful bleeding is required to get all of the air out of the system. Small bubbles can form in the fluid that will form large bubbles over time. It may be necessary to do a series of bleeds.
• DOT5 is slightly compressible (giving a very slightly soft pedal), and has a lower boiling point than DOT4.
• DOT5 is about twice as expensive as DOT4 fluid. It is also difficult to find, generally only available at selected auto parts stores.

DOT5.1
DOT5.1 is a relatively new brake fluid that is causing no end of confusion amongst mechanics. The DOT could avoid a lot of confusion by giving this new fluid a different designation. The 5.1 designation could lead one to believe that it's a modification of silicone-based DOT 5 brake fluid. Calling it 4.1 or 6 might have been more appropriate since it's a glycol-based fluid like the DOT 3 and 4 types, not silicone-based like DOT 5 fluid. (In fact, Spectro is marketing a similar new fluid which they are calling Supreme DOT 4, which seems less confusing.)
As far as the basic behavior of 5.1 fluids, they are much like "high performance" DOT4 fluids, rather than traditional DOT5 brake fluids.
Advantages:

• DOT5.1 provides superior performance over the other brake fluids discussed here. It has a higher boiling point, either dry or wet, than DOT 3 or 4. In fact, its dry boiling point (about 275 degrees C) is almost as high as racing fluid (about 300 degrees C) and 5.1's wet boiling point (about 175 to 200 degrees C) is naturally much higher than racing's (about 145 C).
• DOT5.1 is said to be compatible with all rubber formulations.

Disadvantages:

• DOT5.1 fluids (and Spectro's Supreme DOT4) are non-silicone fluids and will absorb water.
• DOT5.1 fluids, like DOT3 & DOT4 will eat paint.
• DOT 5.1 fluids are difficult to find for sale, typically at very few auto parts stores, mostly limited to "speed shops."
• DOT 5.1 will be more expensive than DOT3 or DOT4, and more difficult to find.

General Recommendations: 1.If you have a brake system that doesn't leak or show any other signs of failure, but has old seals in it, don't change fluid types as a result of reading this article. If it isn't broken, don't "fix" it -- you may simply break it instead!
2.Flushing of the brake system every couple years to remove any absorbed or collected water is probably a good idea to prevent corrosion, regardless of the type of brake fluid used.
3.DOT3 is dangerous to use in cars with natural rubber seals, and thus should not be used in such cars, except as a temporary "quick fix to get me
home" solution. (If this is used as a "get-me-home" solution, bleed the system as soon as possible, and be prepared to replace all your seals.)
4.DOT3 is an adequate brake fluid for use in later cars, although it is rarely preferred. My recommendation would be to simply not use it.
5.DOT4 fluid, for a slight increase in cost, will give significantly increased resistance to moisture absorption, thus decreasing the likelihood of corrosion
compared to DOT3.
6.DOT4 fluid has a higher boiling point than DOT3, making it preferable for high performance uses such as racing, autocross, or excessive use of the brakes in mountainous areas. For even greater braking performance, consider going to DOT5.1 or a high-performance version of DOT4 fluid.
7.DOT5 is a good choice for the weekend driver/show car. It doesn't absorb water and it doesn't eat paint. One caveat is that because it doesn't absorb water, water that gets in the system will tend to collect at low points. In this scenario, it would actually be promoting corrosion!
8.DOT5 is probably not the thing to use in your race car although it is rated to stand up to the heat generated during racing conditions. The reason for this recommendation is the difficult bleeding mentioned above.
9.When changing from one fluid type to another, as a minimum, bleed all of the old fluid out of the system completely. For best results, all the seals in the system should be replaced.
10.As always, your experiences may vary.

 

[Blacksheep Josh]

I think I use Prestone's Dot-3 brake fluid whenever I need it.

It was actually an accident I picked it up the first time, it was the same color as the steering fluid bottle next to it. Imagine trying to replace all the steering fluid when I realized I put brake fluid in there...

 

[jd4242]

good info i don't know what dot it was and now i cant find the bottle but i know it was synthetic and defiantly flushed the system pretty well at least to where all new fluid was coming out at every wheel but i will have to check on what kind it was now

 

[jd4242]

ok new question anyone know if we have 2.2 tall rotors in the front or 2.5 tall rotors o and its for a 92 ex

 

[glfredrick]

Measure...

 

[jd4242]

really wow why didn't I think of that umm maybe because I can't at the moment!!but hey thanks for the advice I will when I can o and anyone else that may have real knowledge feel free to help me out till I can find out for myself

 

[glfredrick]

I wan't really trying to be flippant... Sometimes measuring what you have is the best way to know what you have. Someone else may have the other size.

 

[XxxMonoxideChild]

i did my rear end disc conversion like 2 months ago. was EXTREMELY easy.

if you click on my sig, you will see photos and everything i did.

you dont need to buy new brake lines. the stockers line right up. but when you get the disc rear end. also get the little line on top of the rear end, and get the distribution block also. then it will bolt up.

also, if your not a big rock crawler, grab the sway bar off the 2nd gen also. its a massive upgrade over our 1st gen one. and bolts right up. makes street driving mucho nicer. lol.

 

[jd4242]

i did my rear end disc conversion like 2 months ago. was EXTREMELY easy.

if you click on my sig, you will see photos and everything i did.

you dont need to buy new brake lines. the stockers line right up. but when you get the disc rear end. also get the little line on top of the rear end, and get the distribution block also. then it will bolt up.

also, if your not a big rock crawler, grab the sway bar off the 2nd gen also. its a massive upgrade over our 1st gen one. and bolts right up. makes street driving mucho nicer. lol.

yea i asked you a question about why did you use the mc from a newer one, every body is saying do it,dont do it i was just get opinions i understand that the new mc was made for rear disc but it was also made for dual piston front calipers also so i was just going to adjust the bar on the power booster but what does that really do??

 

[XxxMonoxideChild]

from when i searched, a few had ran the stock 1st gen one without issue after adjusting it.

i ran the 2nd gen one cause i thought it would be up to the added task of the new rear disc's. plus when i got my rear end, i also grabbed ALOT of extra parts. including the master, and even brake booster off the 2nd gen. because i knew the guy, and he was only charging me for the rear end, not all the extra crap i grabbed.

i didnt run the 2nd gen brake booster cause it has a different bolt pattern. did use the 2nd gen master though. bolted right on, and didnt even adjust the arm at all.

i still havent attatched the emergency brakes though. the cables were different, and at the time i didnt care at all, and just zip tied them out of the way.

 

[jd4242]

update so i got the rears brakkes laying around and waiting on money to get gears and lockers before i do them so im going to do the front wile im waiting and this is what im useing,ill post some pic later when i install them o and im going with the drilled and slotted just because they look better and they are cheap so if they crack ill just replace them
rotors drilled and slotted
http://store.r1concepts.com/Items/I...LORER 91-92 4WD Brake Rotors - E-Line - Front
calipers
http://cgi.ebay.com/ebaymotors/ws/e...0302266620&sspagename=STRK:MEWAX:IT&viewitem=

 

[jd4242]

there here man i didn't realize how much our brakes weigh.im going to paint them the same color as my engine (blue),the rear are going to be the same company as stated above

 

[jason's 94]

looks good

 

[XxxMonoxideChild]

very nice!

i rebuilt my front brakes when i first got the truck after a rubber line blew. so just replaced all the rubber lines, calipers, and rotors. made the truck much nicer (and made me want to the disc swap the rear end) lol. i really wish i had picke dup some slotted rotors though back then. if for anything, at least the "bling" value.

 

[jd4242]

very nice!

i rebuilt my front brakes when i first got the truck after a rubber line blew. so just replaced all the rubber lines, calipers, and rotors. made the truck much nicer (and made me want to the disc swap the rear end) lol. i really wish i had picke dup some slotted rotors though back then. if for anything, at least the "bling" value.

yea my fronts are warped so i got these just because they were like $60 a rotor cheap!!o and they do bling nice in the sun

 

[jd4242]

so the front are on after i finally figured out that i had the wrong rotors.i had the 2.2 and they was wrong the 1st gen with the d35 in it uses the 2.5 rotor.my fronts were so warped all most a 1/4 on one side and the seals and bearings were shot.this thing brakes like a new truck,cant wait to get the rear ones on!!im not going to go through how to do it because its been done but here is the link i used for help.and some teaser pic!!
http://www.explorerforum.com/forums/showthread.php?t=122696

 

[glfredrick]

I just scored rear disk brakes for my project also. Only mine has an 8-lug Dana 60 axle...

Found a great pull-a-part deal -- someone had just went through the entire front end of the donor 77 K30 and replaced the rotors, calipers, pads, bearings, hubs, etc., before sending the project to the salvage yard. All new parts -- total cost was $44.

I'm using Great Lakes Off-Road brake brackets, and the rest of the Chevy front end parts to convert mine to rear disks. Nice setup, simple, clean, and work with my 15 x 10 wheels.

 

[jd4242]

I just scored rear disk brakes for my project also. Only mine has an 8-lug Dana 60 axle...

Found a great pull-a-part deal -- someone had just went through the entire front end of the donor 77 K30 and replaced the rotors, calipers, pads, bearings, hubs, etc., before sending the project to the salvage yard. All new parts -- total cost was $44.

I'm using Great Lakes Off-Road brake brackets, and the rest of the Chevy front end parts to convert mine to rear disks. Nice setup, simple, clean, and work with my 15 x 10 wheels.

d60 you putting that axle in your truck or just taking all the parts?