fast_clean_brake_fluid_change_smart_fortwo_451_using_sealy_vs820_pressure_bleede¶

2 excerpts.

Excerpt¶

youtube.com/auto_knight/fast_clean_brake_fluid_change_smart_fortwo_451_using_sealy_vs820_pressure_bleede · p. 1 · Applies to: 450, 451, 452, 453, 454, #1, ebike

In today's video, I'm going to be carrying out a brake fluid change on the Smart the Easy Way. I'm Steven from Autoite. Welcome to another video. Now, in the absence of workshop equipment, there are very easy ways to carry out a brake fluid change, and there are more complex. You can do it the oldfashioned way where you've got somebody in the car putting the pedal down as you open a bleed screw and then lifting it up once you've closed it and repeat. It gets quite tiresome with a constant down up and you are relying on somebody else to do what you're asking them. But it needn't be that difficult. And historically I've used a kit that involves the use of a spare wheel to provide the pressure to pressure bleed it. But recently, I've bought something a whole lot better, and I'd like to introduce you to it in this video, where I'm going to use it to perform a brake fluid change on the Smart for Two. So, for context, this is what I used to use, and you'll have seen it in many videos. You hook up a spare wheel to this reservoir. It pressurizes this reservoir, and it forces brake fluid from this into the vehicle's reservoir, which means you can then just open up the bleed screws in turn. In reality, these are about 35 quid. They have their limitations, mainly because they bloody leak from here, often from here as well, and it can be infuriating. So, enter this from Celely. I'll unbox it now and show you what we get. Inside the box, you get this, the main unit here. We use this to unscrew this reservoir lid. Once you filled this with brake fluid, you attach this to the brake fluid reservoir of the car. This plugs into here. And these are quality fittings. This does not feel in any way cheap. And once you're happy that that's on tightly, you pump this ideally to 10 PSI. And then you can go around, release each bleed screw in turn and drain out your desired quantity. Now, I have used this already, so there is some brake fluid in here. I just wanted to try it out before I made the video, but I haven't used it on the Smart, and this car has not yet had a brake fluid change during my ownership. The brake fluid reservoir on these cars is right here. It's important to remember that brake fluid has a very damaging effect on paintwork. It will strip it from the car. So, don't spill any on the car. And if you do, wash it off with plenty of water and immediately. We remove the cap and we fit this. This swivels all the time, which makes it easier even when this is tight. It's now time to fill this with some brake fluid. I use DOT 4 synthetic brake fluid. Definitely don't use any less than dot 4. Definitely not dot three. That's really old hat. Now, I have to stress this needs to be tight. And I did need to use this to fully tighten it. Tightening this by hand was insufficient to prevent air loss from here once we pressurize it using this, which will come later. In fact, I was quite surprised how tight I had to get this. I was actually worried at first that uh it was defective, but it wasn't. I just had to really tighten it with this. Back at the vehicle with this placed in a steady place on the car, we can now connect this And with the vehicle raised on one side and secured, we can begin work at the bleed screws on each wheel. But first, we need to pressurize this to 10 PSI. Starting at the back of the car, remove the dust cap for the bleed screw. And I need an 8 mm spanninner for these bleed screws. You can remove the wheel to make it easier if you wish. I don't need to. Now I'm going to see if this will release. These are very prone to seizing and if they are seized and you force the issue, they will snap off. They don't usually leak at that point. They just break off. But obviously they could. But if that happens, it's easier just to change the wheel cylinder. This is moving and that's great. So I can now push some tubing over that which feeds neatly into an old bottle of brake fluid. I can increase the flow by loosening that a little more if I need to. But

Excerpt¶

youtube.com/auto_knight/fast_clean_brake_fluid_change_smart_fortwo_451_using_sealy_vs820_pressure_bleede · p. 2 · Applies to: 450, 451, 452, 453, 454, #1, ebike

that's bleeding through quite nicely. And you can hear it back up front. All I need to do at this point is periodically check this gauge to ensure we stay around the 10 PSI mark. And if we start to drop, pump this a little more. Now, some people like to siphon out a quantity of brake fluid from the master cylinder reservoir to ensure you get new fluid straight in there. I mean, yeah, you can. It's very messy. What I prefer to do is to just bleed more than usual out of the first wheel that purges that reservoir of all the old fluid. So, drain at least a good half liter out of the first wheel that I bleed. That's my way of doing it, but we're all different. I want to minimize spillage because I hate working with brake fluid. And while half a liter bleeds through that near side rear, I'm going to enjoy a nice cup of fresh French ground coffee. Well, obviously there's water in there, too. It's not just ground coffee, but it's very good. With this around half full, close the bleed screw and remove the pipe. Refit the dust cap. This is such a mess-free way of doing things. We can now move to the front. To avoid removing the wheel, I use an old door mirror glass and I can see exactly what I need to do there. We need an 8 mil spanner for the front, just the same as the rear. And as with the rear, we just loosen the bleed screw and at the pressure, force the fluid through. You'll generally find that the flow of brake fluid is faster at the front due to the way brakes are set up on most cars. You're also a whole lot nearer to the reservoir. It probably goes without saying, but I'll say it anyway. Make sure you've got enough brake fluid in here to do the job. You don't want to end up in a situation where it gets too low and you risk drawing air into the system. So keep the level decent here. You would have to depressurize the whole thing to refill it, and that's not necessary if you plan it right. Likewise, at intervals, it's worth just checking to make sure there's no leakage. But this system is really good. Very leak free, very easy. Tighten the bleed screw. Remove the pipe. With this one nearly full, we swap over to another empty container. We are now ready to do the other side. Basically repeat the same. Do I even need to show you this quick recharge? And last of all, that offside front. With all the bleed screws tightened, I need to depressurize this before I start undoing things or there'll be brake fluid everywhere. So, I just very slightly loosen this till it hisses, which releases the air. Can see the gauge dropping. Okay, so that's depressurized now and only now. Can I disconnect this and remove this from the vehicle? The level will likely be higher than it needs to be. So, I use a syringe to remove any excess and keep going till we're at the correct level. And have a good clean up. Make sure there's no break fluid anywhere. As I've already said, it is your paintworks enemy. We check we've got a nice firm pedal, which we have. refit the front panel. Well, that's it for today's video. I do hope it was useful. Look out for another video coming soon where instead of pressure, we rely on suction and we use this Pella 6000 pump to carry out an oil change on the Smart for Two. Please don't forget to like and subscribe and I look forward to seeing you again very soon.