Kaputnik

Since I wanted to change my rear pads and get the rotors resurfaced last week, I thought I’d change out the brake fluid too, which was looking a bit dark.

I know there is an excellent DIY on using the Motive power bleeder here on the boards. Yet I couldn’t bring myself to spend $60-80 on something I would so rarely use. Gravity bleeding brakes is very popular in the Honda S2000 community, and I can personally attest to the effectiveness. So I thought I would give it a try on my RDX. I figured I could do no harm unless I ran the MC dry (I used my phone's timer so I couldn't wander off if I saw something shiny).

I used the sequence LF, RF, LR, RR. Drained out most of the old dark fluid through the RF line, which took about 40 minutes and a few of refills of the master cylinder when it hit the low mark. After that, the remaining calipers needed about 10-15 minutes each to bleed clear. I needed just shy of 3 bottle of Honda DOT 3 to do the job. I am not advocating gravity bleeding over any other approach. But I will say it was remarkably easy, reasonably quick and the results were great – firm pedal and quiet, smooth braking.

I’m sure some will disagree with this approach. For sure, of any automotive topic I’ve ever researched on the internet, I’ve found more hearsay, conjecture, anecdotal theories and just plain BS related brake bleeding than the existence of Bigfoot.

TheWrench116

iTrader: (1)

I do it to. after I replaced the rear brakes and installed stainless braided lines. worked for me.no issues.

protoRDX

Dont we have ss braided lines in stock?

Kaputnik

Thanks - good to know!

proof

Haven't bled brakes before.
Would love to attempt this gravity bleed. Fluid is nasty old and I don't want to spend money on a bleed system or a mechanic. I have time on the weekends.
Kaputnik, would you be willing to slap together a quick DIY with pics?

Kaputnik

I'll at least write something on how I did it, but probably without photos in this case. It's very simple.

In the meantime get your fresh brake fluid (be safe and buy 4 bottles, probably use only 3) and some clear vinyl tubing. I used the OEM Honda brake fluid, and about 1 foot of 1/4" i.d., 3/8" o.d. tubing.

proof

Done and done.

I googled around, and I get the jist of it, but wouldn't mind a quick write up from you.

Did you have any trouble with the bleed screw/valves? I've never bled brakes before, but i've heard from people that do, they often have problems with seized valves.

Thanks for replying back, btw. The DIY section is completely dead. Most of the threads are filled with dead imageshack links. Kind of sucks for someone who just got an older model RDX like me. Most of those guys who wrote the DIY threads 5,6,7 years ago don't even have an RDX or browse here anymore.

Kaputnik

OK Proof, here is some more info. I learned about gravity bleeding from the S2000 community, where it’s a very popular approach. Here is a great link with photos that tells you pretty much everything:

DIY: Brake Bleed (Gravity Method) - S2KI Honda S2000 Forums

They don’t sell the blue brake fluid anymore in the US. Since your old fluid is dark, you should see the change in color as the new fluid passes into the tubing at the bleeder. DO NOT use the S2000 bleed order, use the bleed order left front, right front, right rear, left rear (737 JOCK says it’s directly from the RDX factory service manual). Ignore the bleed order in my first post, I cut and pasted the wrong one (doh!), but did what I mentioned here. The flow rate on the RDX is very good; much better than my S2000, since there is good vertical distance between the bleeders and the MC.

This is not really a DIY, just some pointers. I also don’t have time to take photos.

Park someplace level and safe to work. At this point, I am going to assume you know how to loosen lug nuts, safely jack up the RDX, properly place jack stands and remove wheels. You can only remove one wheel at a time or put the whole vehicle up on jack stands.

Next put some shop towels carefully around the MC in case of spilled brake fluid. I was able to pour directly from the bottle into the MC without spilling. I also didn’t remove the old fluid directly from the MC reservoir since my fluid was not too bad. Nor did I want to stick a baster in there and mess things up. But you might want to do that if your fluid looks really bad, or “nasty” as you say, lol. In the end, I never used a turkey baster.

I removed the rubber caps and sprayed a little penetrating lubricant on the bleeders the night before since mine looked rather crusty (it had an earlier life in the Midwest). The bleeders opened easily the next day and the threads were very clean.

Place a short length (about 12”) of the tubing on the bleeder, and loosen the valve with the 10 mm wrench. I used the closed end of the wrench and threaded the hose through it to loosen the bleeder initially. Remove the wrench, put the end of the tubing into a clear plastic container (I used a 16 ounce water bottle) and then open the valve fully. You don’t have to turn very far before fluid starts coming out into the hose. Make sure the end of the hose is lower than the bleeder. After each wheel I dumped the old brake fluid into a larger storage container.

I cleared the entire MC through the LF line, which took about 40 min and used a full bottle of fluid. Just be careful not to let the level of the brake fluid drop too far in the MC such that you get air in the lines. I played it safe and added fluid each time it hit the “low” indicator. You might set a timer for every 10 min just so you don’t go wandering off and forget what your doing. Once the line runs with fresh fluid, close the bleeder. Refill the MC and move onto the next wheel, the RF. Subsequent lines go fast since you have already replaced fluid in the MC – about 10-15 minutes each. Once you bleed the LR line, you are done. Fill the MC to the correct level. Make sure the cap is clean and replace. Double check that you closed all your bleeder valves! Your brake pedal should pump up rock solid in about three pumps even before you start the car. Take it for a drive and the brake pedal should feel great. I checked everything after the drive and again the next day for any changes in fluid level or leaks. Brake feel has been great for 4000 miles now! If your fluid is really old, you may feel a big difference after changing out the fluid.

This process is really easy if you are not in a hurry. There is almost nothing you can screw up, other than forgetting to fill the MC with fluid in time, and letting air into the system. In that case, you would need to do a traditional pedal pump or pressure bleed to clear the lines of air. Let us know how it goes, and post or PM questions – there are folks here a lot smarter than I am. Hope this helps.

proof

Thank you Kaputnik, cheers brother.

It all sounds good, as i've been reading around a bit. That's the thing with youtube and google. You can get a rough idea how to generally perform maintenance, but in the end of the day, every car model and manufacturer are different. Certain things, such as bleed order, are different, for example. Maybe not hugely important, but I like to do it right.

I like that I can basically clear out the MC on the first left front caliper.
A few questions.

First, left, as in sitting in the drivers seat, looking forward.
So left = Drivers side, right = passenger side, correct?

Can I just jack the front up first, do front left and right, lower, and do the back? Does the car have to be level to bleed well?
Only have one jack and 2 stands, don't feel like lifting the whole car at once in my small garage.

I might just use a big syringe I have (used to suck out PS fluid) to suck out some of the old stuff in the MC. I won't take out too much as I don't want to deal with air.
After that i'll fill the MC full with the fresh stuff, and start bleeding.

hues10

Do I even need to jack up the car and take the wheels off? It looks like I can get to the bleeder screws by crawling underneath or by going up some ramps. Sorry, I am older and don't feel like hurting the back by taking wheels off. I can crawl and shimmy enough. And no jokes about I should probably be driving a Buick, though that is what my 83 year old Father has

Kaputnik

Yes you are correct on the left vs right. Left = driver side. You start at the left driver side and continue clockwise.

The big syringe should work well to remove fluid from the MC. You can basically remove everything from the MC that you can easily reach, since you won't be able to draw out of the lines or anything.

To both OP and hues10, yes you can jack up one wheel at a time. Or if you can reach the bleeder easily enough, you do not need to remove the wheel at all. I happened to have had mine on 4 jack stands since I was changing out the pads. I don't think the car needs to be perfectly level, since again there is a lot of vertical distance between the MC and bleeder valves. Gravity will clear everything. It is more critical on my S2000, since the car has such a low profile there is just enough gravity to do this!

Good luck! Post how it turns out.