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Old 7th October 2014, 17:11   #16
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Default DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by aah78 View Post
If you regularly do DIY work that requires you to spend time under the car then I'd definitely recommend investing in a pair of jack stands.
Leaving the car on a jack - hydraulic or mechanical for extended periods is not advisable.

.

I would put it a bit stronger than that; you should not spend any time under a car that is up on a jack, any jack. You should always put it on jack stands. Every year in the UK alone several DIY car mechanics get killed because they crawled under a car on a jack. Putting the car on jack stands should be basic safety precaution to any work that requires you to get under the car.

In my experience its usually possible to bleed the brakes without the need to jack up the car. Just a bit more fiddly. But on some cars, bits get in the way.

I prefer bleeding by means of an easy bleed device or such. Not only is it easier, especially if you are on your own, it also means you don't need to pump the brake pedal. Especially on older brake master cylinder there will be a built up of dirt inside the cylinder at the far end of the stroke. By stepping on the brake pedal repeatedly you shove the seals through this dirt. Try and open up an old master cylinder and you are likely to feel a little ridge. As pointed out, pumping the brakes is a perfectly accepted method, but be aware the effect I describe is rarely immediate. It shows up after many thousands of kilometers. Some type of brake cylinder brands/models are more susepticle to it as well then others.

If after proper bleeding the brakes still feel spongy or mushy its time to look further. Here's what I would do. Step on the brakes with all your might and hold it for thirty seconds or so. Does the pedal move down? Even if its a tiny bit, changes are there is something wrong with the master cylinder or you might have a leak somewhere else. Although its entirely possible to overhaul most brake cylinders, I will usually just install a new one. Its just to critical to be messing around with.

Check the complete mechanical linkage part and anchoring of the brake pedal, booster, master cylinder and brake linkage. I once had a problem with the brakes feeling a bit spongy, which was the result of the master cylinder not properly fastened onto the booster. have someboy press the brake pedal repeatedly and look under the hood at the brake booster and master cilinder and the pipes. Nothing, other then the brake pedal linkage should move, everything should be rock steady. If not investigate and fix.

The next thing I would try I'm not sure can be done in India. I would take the car to a workshop that has a vacuum brake flush system. Sometimes, some tiny air bubbles just remain behind, no matter how much brake fluid you push through. With the vacuum system you create a vacuum at the brake bleed nipple. By lowering the pressure any small air bubbles come out. Lastly I would take a very good look at the various brake hoses. Old ones tend to get porous from the inside out. Which effectively means they sort of create an elastic buffer for the brake fluid. If its real bad, you might actually see the hoses swell if somebody steps on the brake pedal very hard.

Its one of those cases where if you have run out of all options you might consider replacing the brake hoses, for lack of alternative s. If you ever do, cut the old hoses open length wise and you might be surprised what you see!

I don't test the brake fluids, i just flush the brake system on regular intervals. My comment was about that you cant really conclude anything on the colour by itself. In the past, just because I wanted to know I have taken some test samples over a longer period of time on multiple cars. i wanted to get a feel for how much moisture does get absorbed over time by the brake fluid. Even after two years it was minute. But I guess it depends a lot on the circumstances. To add why this moisture is a problem; the moisture comes from the air as the brake system is open to the air. Moisture in the brake fluid can cause additional wear and tear in the brake system. In addition it can lower the boiling point of the brake fluid, thus resulting in brake fading earlier then designed.

Jeroen
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Old 7th October 2014, 17:23   #17
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by Jeroen View Post
Step on the brakes with all your might and hold it for thirty seconds or so. Does the pedal move down? Even if its a tiny bit, changes are there is something wrong with the master cylinder or you might have a leak somewhere else.

Check the complete mechanical linkage part and anchoring of the brake pedal, booster, master cylinder and brake linkage. I once had a problem with the brakes feeling a bit spongy, which was the result of the master cylinder not properly fastened onto the booster. have someboy press the brake pedal repeatedly and look under the hood at the brake booster and master cilinder and the pipes. Nothing, other then the brake pedal linkage should move, everything should be rock steady. If not investigate and fix.




Jeroen
In my Figo this happens, this started after the so called Brake fluid change from the Ford A.S.S during their so called yearly fluid change.

What do you think is the problem?


Quote:
The next thing I would try I'm not sure can be done in India. I would take the car to a workshop that has a vacuum brake flush system. Sometimes, some tiny air bubbles just remain behind, no matter how much brake fluid you push through. With the vacuum system you create a vacuum at the brake bleed nipple.
None of the dealers here do this, I seen Honda, Ford, Maruti, they don't use such tech here. Its the old way of doing things. Open the valve and let the oil come out with someone pumping the pedal.
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Old 7th October 2014, 17:29   #18
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by Captain Slow View Post
In my Figo this happens, this started after the so called Brake fluid change from the Ford A.S.S during their so called yearly fluid change.
Could be air entrapment in the brake lines or the fluid change wasn't done correctly fiddling with the master cylinder / lines.

Anurag.
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Old 7th October 2014, 17:31   #19
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by Captain Slow View Post
In my Figo this happens, this started after the so called Brake fluid change from the Ford A.S.S during their so called yearly fluid change.

What do you think is the problem?
What exactly happens? Does the pedal sinks down after keeping it depressed for a while in a running or stationary engine? If yes, then look for leakages in the hydraulics. And treat this as an emergency.

Please also note that pressing the pedal a few times with the engine not running will make the pedal hard (as you use up the vacuum in the booster). If you keep it depressed and fire the engine, the pedal will go down a little. That is normal.

Regards,
Saket

Edit: Any updates on the brakes SunnyBoi?

Last edited by saket77 : 7th October 2014 at 17:33.
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Old 7th October 2014, 18:11   #20
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by a4anurag View Post
Could be air entrapment in the brake lines or the fluid change wasn't done correctly fiddling with the master cylinder / lines.

Anurag.
Quote:
Originally Posted by saket77 View Post
What exactly happens? Does the pedal sinks down after keeping it depressed for a while in a running or stationary engine? If yes, then look for leakages in the hydraulics. And treat this as an emergency.

Please also note that pressing the pedal a few times with the engine not running will make the pedal hard (as you use up the vacuum in the booster). If you keep it depressed and fire the engine, the pedal will go down a little. That is normal.

Regards,
Saket
When the car comes to a complete standstill, or if the car is stationary and you press hard on the brake pedal, after a few seconds the pedal goes down a little bit more.
This started happening after the last service where the brake fluid was replaced. I thought this to be normal, until today when I read Jeroen's post

haha! yes Saket No this didn't happen when the engine was off, I understand with the engine off, there wont be any pressure so the brake pedal will be hard. The engine was always running with the car turned on.
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Old 7th October 2014, 19:46   #21
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Quote:
Originally Posted by Captain Slow View Post

When the car comes to a complete standstill, or if the car is stationary and you press hard on the brake pedal, after a few seconds the pedal goes down a little bit more.
How is braking feel otherwise?

I'd suggest to bleed the system once to be sure.

Anurag.
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Old 8th October 2014, 11:26   #22
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by a4anurag View Post
How is braking feel otherwise?

I'd suggest to bleed the system once to be sure.

Anurag.

Not too bad, It was a bit spongy after I got the car back. So I replaced the OEM pads which had about 50% of life with Delphi metallic pads.
This improved the brake bite, but the mild spongy feeling was still there.
Is this OK? Do think I need to bleed it once more?
I am not sure the A.s.s bleed the lines or just replaced the oil in the reservoir.
p.s
Car is not longer in warranty, I can get it done at a FNG or a DIY
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Old 8th October 2014, 11:29   #23
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by Captain Slow View Post
I am not sure the A.s.s bleed the lines or just replaced the oil in the reservoir.
p.s
Car is not longer in warranty, I can get it done at a FNG or a DIY
Sponginess does relate to air in the brake lines.

Do get the whole thing bled once at an FNG or a DIY (if you can do it).

Anurag.
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Old 10th October 2014, 15:14   #24
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

Quote:
Originally Posted by Jeroen View Post
Shortest first, then the next, longest length last.
VS

Quote:
Originally Posted by saket77 View Post
Personally, I would advice you to bleed the wheel farthest from the master cylinder first, typically, working towards the closer ones in the sequence; unless the owner's manual suggests a different order.
^ Why these two different schools of thought? What's the reasoning for each?

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Originally Posted by SunnyBoi View Post
I'll fill the vial again with brake fluid and leave it in the open air for a week. That should clear things out I guess (or make it murky )
When doing tests like this you should also have a 'control'. In this case, another vial left in the same location, without the water mixed in. Ideally, a 3rd one too - sealed / not exposed to the atmosphere.

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Originally Posted by SunnyBoi View Post
Do you mean the straight groove across the pad? I believe that exists for easy check of brake pad wear. Absence of the same shouldn't affect the performance of the pads though.
Doesn't it also have some effect on preventing screeching noise from the brakes? (Intended or unintended, I'm not sure).

Quote:
Originally Posted by Captain Slow View Post
When the car comes to a complete standstill, or if the car is stationary and you press hard on the brake pedal, after a few seconds the pedal goes down a little bit more.
If its holding steady for a while, and then there's a sudden drop in the pedal - its probably something else (not moisture/air in the lines).

cya
R
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Old 10th October 2014, 15:49   #25
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by Rehaan View Post
Why these two different schools of thought? What's the reasoning for each?
Many philosophies suggest that unless the manufacturer specifies a particular sequence depending on the design of the hydraulic systems, any order of bleeding the brakes can be resorted to. However, why I think the farthest wheel to be bled first is because during the flush, bleeding the farthest wheel will clear all older fluid in the lines & the master cylinder.So while working with the brake pedal while bleeding other wheels, the reverse action of fluid will not suck back old fluid. Also, bleeding the longest line first means taking out most of the brake fluid at the first go. So, the chances of running out of brake fluid from the reservoir is comparatively lesser while bleeding the shorter lines. Not to mention that one will have to start the entire job all over again if the reservoir is devoid of fluid & air enters the system.

This is my understanding. If anyone has another point of view, it will be an enlightening discussion.

Regards,
Saket
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Old 10th October 2014, 16:05   #26
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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^ Why these two different schools of thought? What's the reasoning for each?
Very simple explanation, I got mine mixed up! It's longest brake line first etc! (or as Saket puts it the one furthest away)

In my defense, and I have said so many, many times on this forum, don't believe everything you read on the Internet.

Jeroen

Last edited by Jeroen : 10th October 2014 at 16:29.
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Old 10th October 2014, 16:27   #27
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

Continuing from where I left of, I did managed to drive about 150KMs to Bangalore safely. The brake pads have now more or less bedded in, the brakes now feel exactly how they did before I got the pads changed.

In the meanwhile, I was doing some checks on the available DOT4 fluids. The usual TVS Girling seemed, well, quite ordinary and for the next fluid change I wanted a good fluid that would last well for the next 2 years.

Other contenders were Castrol DOT4 and Motul DOT3&4. Castrol has a Dry/Wet boiling point of 265*C/155*C whereas the Motul has 245*C/160*C. Then entered a dark horse by the name of Petronas Tutela Top-4, which has the statictics at 270*C/180*C. It has a higher wet boiling point, even meeting the minimum temperature standards set by DOT 5.1! Cost wise, Castrol 500ml was Rs220, Motul DOT3&4 was Rs 550 and Top-4 was Rs399 for 1L. This made my choice of getting the Petronas Tutela TOP-4 a no brainer.

I managed to get 2 liters from Vecto Motors, the Fiat ASS where its available OTC. I was glad to see Fiat uses superior grade of fluids in their cars ! (Top tip, the Petronas Tutela TechnyX 75W-80 is the only GL4 Fully Synthetic Gearbox fluid available in India, its standard on the Punto and Linea)

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Recently I discovered that my Clutch Master Cylinder has a very tiny leak, couple of drops seep out a week and there has been no noticeable drop in fluid levels. Since I'm getting the whole system overhauled, I'd better get a new Clutch MC put in before I started the complete drain and bleed process again. I'll get the FNG to fix the front bleed nipples for me as well. Hoping to get the work all done by Saturday and I can bleed the car on Sunday.

Quote:
Originally Posted by Jeroen View Post
I prefer bleeding by means of an easy bleed device or such. Not only is it easier, especially if you are on your own, it also means you don't need to pump the brake pedal. Especially on older brake master cylinder there will be a built up of dirt inside the cylinder at the far end of the stroke. By stepping on the brake pedal repeatedly you shove the seals through this dirt. Try and open up an old master cylinder and you are likely to feel a little ridge. As pointed out, pumping the brakes is a perfectly accepted method, but be aware the effect I describe is rarely immediate. It shows up after many thousands of kilometers. Some type of brake cylinder brands/models are more susepticle to it as well then others.
Jeroen
Jeroen, needed some advice for Reverse bleeding. On my bikes I'd start pushing brake fluid from the caliper and observe the MC reservoir as to when the air bubbles stop popping out. However with cars its very difficult, actually impossible when doing the rear brakes to observe the reservoir for air bubbbles. I was thinking of blindly pumping 200ml from every line, I'm assuming 200ml should suffice to flush a single line. If it doesn't, probably I'll add 100ml more. Does this seem plausible or can you suggest a better way to tackle the same? Plus, do I bleed the clutch first or last?
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Old 10th October 2014, 16:35   #28
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

Great effort.
Brake bleeding is one of the maintenance step people used to skip, but is is very important.
Two things are there:

- Changing the brake fluid once it loses the viscosity, usually it happens due to high temperature produced during braking and environmental factors.

- Periodical bleeding is a must to avoid spongy brakes. It happens mainly due to air pockets created due to moisture evaporation at high temperatures and sometimes the fluid itself will reach its boiling point, thats why those who do spirited drives prefer a good quality Dot4 fluid with high boiling point than stock fluid.

Pedal pumping is one method, but it wont make sure the complete removal of bubbles from the line. Another proven technique is pressure bleeding, you can get pressure bleeding kits or it can be made yourself with a pump sprayer, pressure gauge and a master cylinder cap rig. The tyre sequence depends on the brake line design, start from the farther exit from the master cylinder and end with the closest to reduce wastage.
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Old 10th October 2014, 17:01   #29
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

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Originally Posted by SunnyBoi View Post
Jeroen, needed some advice for Reverse bleeding. On my bikes I'd start pushing brake fluid from the caliper and observe the MC reservoir as to when the air bubbles stop popping out. However with cars its very difficult, actually impossible when doing the rear brakes to observe the reservoir for air bubbbles. I was thinking of blindly pumping 200ml from every line, I'm assuming 200ml should suffice to flush a single line. If it doesn't, probably I'll add 100ml more. Does this seem plausible or can you suggest a better way to tackle the same? Plus, do I bleed the clutch first or last?
In theory that should suffice, however I would srongly recommend to get another person to observe to make sure or get an easybleed or similar. That allows you to pressure bleed as per CMS suggestion and all by yourself.

On the clutch, follow the same approach as for the brake lines. So the shortest last (this time it is correct). Most likely your connection from the reservoir to the master cilinder is shorter the. Any of the brake lines, so leave it for last. It shouldnt matter really, but at least by then the reservoir will have been filled completely with fresh brake fluid

Another tip, when I start bleeding brakes or flushing them I usually extract the old brake fluid from the reservoir first and fill it up with new. Otherwise you are just pushing old fluid through the system. If the clutch is fed from the same reservoir you will probably find the reservoir is filled into two distinct reservoirs by means of a divider, thus ensuring redundancy between the two systems. Usually the clutch part feeds from overflow from the brake part. So you need to extract from both.

Here a picture of my Easybleed and the big syringe I use to extract fluid from the reservoir


One small word of caution using pressure bleeding. On system with one reservoir for both brake and clutch, the clutch mastercilinder is usually just gravity fed from the reservoir. So that is a pipe or sometimes a hose that is not pressurized. Make sure its probably fastened before applying the pressure on the reservoir. I learned the hard way on one of my cars. It was just a simple hose with no hose connectors, i opened the pressure valve, the hose popped off and the reservoir emptied out under pressure over my car and me. Huge mess and the brake fluid is very corrosive on paint and so. So make sure you check that clutch- reservoir connection before you pressure on the system!

Jeroen

Last edited by Rehaan : 10th October 2014 at 17:36. Reason: Reducing image size :)
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Old 13th July 2016, 16:27   #30
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Default Re: DIY: Flush / Bleed the clutch & brake fluids

In our Xylo E8 ABS Nov 2009 that has covered 2,68,700+kms, I was draining the old brake fluid at wheel end and by mistake I injected air in the brake system.

Now the brake pedal is sinking down when I press the brake pedal. But it returns to its default position after its released. The braking power has reduced drastically. I got the brake system bleeding done but no improvement.

If I pump the brake pedal 3-4 times during brake application (car in motion), the brakes get applied. Even at speed of 90-100kph, 3-4 Times pumping does the trick.
Has the master Cylinder conked off?
I have got the Master Cylinder replaced around 2-2.5 years and 50-60000kms ago.
Mods please move to appropriate thread If need be.
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