If you're staring at your engine bay trying to find the عکس پیچ هواگیری ال 90, you're probably dealing with a car that's running a bit too hot or a heater that's blowing frustratingly cold air. It happens to the best of us. The Renault Logan, or Tondar 90 as many know it, is a legendary workhorse, but like any car with a pressurized cooling system, it occasionally gets "gas" in its veins. This air needs to come out, and that's where the air bleed screw comes into play.
I remember the first time I tried to find it. I was convinced it would be this big, obvious metal bolt, but it's actually much more subtle than that. Usually, if you search for an image or عکس پیچ هواگیری ال 90, you'll see a small, black plastic cap that looks suspiciously like the one on your tire's air valve. Finding it is half the battle; the other half is not breaking it.
Why you need to find that bleed screw
Before we dive into the "where," let's talk about the "why." Your L90 relies on a constant flow of coolant to keep the engine from turning into a very expensive paperweight. When you change your coolant, or if there's a tiny leak somewhere, air gets trapped. Since air doesn't move heat as well as liquid, you get "hot spots."
If you've ever noticed your temperature needle jumping around like it's at a concert, or if your cabin heater feels like an air conditioner even when it's set to max, you've likely got an air bubble. Looking at a عکس پیچ هواگیری ال 90 helps you identify exactly what you're looking for so you don't accidentally unscrew something that shouldn't be touched.
Where is it hiding?
The L90 is a bit unique because it actually has two main spots where air likes to hide. Most people are only looking for one, but to do the job right, you really need to know both.
The Thermostat Housing Screw
The first one is usually located right on the thermostat housing. If you stand in front of the car and look toward the engine, follow the thick hose that goes from the top of the radiator back toward the engine block. Right where that hose connects to the engine, you'll see a black plastic housing. On top of that housing, there's a little plastic cap. This is the most common عکس پیچ هواگیری ال 90 you'll see online.
The Heater Hose Screw
The second one is a bit further back, closer to the firewall (the wall between the engine and the cabin). Follow the two smaller hoses that go into the dashboard area—these are your heater hoses. One of them will likely have another one of those little plastic caps. If you only bleed the air from the front one, you might still have a cold cabin because air is trapped in the heater core.
What does it actually look like?
If you don't have the عکس پیچ هواگیری ال 90 right in front of you, just imagine a tire valve cap but made of a slightly harder plastic. It's usually black, though sometimes they get dusty and look gray. They have ridges on the side so you can turn them with your fingers.
One thing to keep in mind: these things get brittle. They spend their lives being heated up and cooled down, which makes the plastic weak over time. If you're about to open it, please, be gentle. I've seen way too many people snap the head off, and then you're in for a much bigger headache involving pliers and possibly a new thermostat housing.
Step-by-step: How to bleed the air
Once you've identified the spot using your عکس پیچ هواگیری ال 90 as a reference, the process is pretty straightforward, but you have to be careful.
- Wait for it to cool down: Never, ever try to open these when the engine is boiling hot. You'll get a face full of steam, and that's a trip to the hospital nobody wants. Wait until it's warm to the touch, but not scalding.
- Open the reservoir: Take the cap off the coolant expansion tank. This allows the pressure to equalize.
- The slow turn: Locate the screw and turn it slowly counter-clockwise. You'll hear a "hissing" sound. That's the air escaping.
- Wait for the stream: Keep the screw open until the bubbling stops and a steady stream of liquid starts coming out.
- Tighten it back: Don't over-tighten! Just snug it up. If you use a wrench on these plastic caps, you're asking for trouble. Finger-tight is usually plenty.
What if the screw is stuck?
Sometimes you look at your عکس پیچ هواگیری ال 90, you reach for it, and it won't budge. This is common if it hasn't been touched in years. Don't force it with a pair of heavy-duty pliers immediately. Try a bit of WD-40 or a similar penetrant first. Let it sit for ten minutes.
If it still won't move, you might have to accept that the plastic has fused slightly. In some cases, mechanics actually prefer to bleed the system by slightly loosening the hose clamp on the main radiator hose rather than risking a broken bleed screw. It's messier, but it works in a pinch.
Why a photo is better than a manual
Let's be real, the owner's manual for the L90 is fine. But it uses diagrams that look like they were drawn in the 80s. A real عکس پیچ هواگیری ال 90 shows you the grime, the surrounding wires, and the actual perspective you'll have when leaning over the fender.
When you see a real photo, you notice things like the proximity to the battery or the way the wiring harness sits next to it. It gives you context that a line drawing just can't match. That's why so many L90 owners spend time searching for these images before they even pick up a tool.
Signs you did it right (or wrong)
After you've found the screw and let the air out, take the car for a quick spin. Watch that temp gauge. It should sit right in the middle and stay there. If it still climbs, you might have more air trapped, or your thermostat might be toast.
Another sign of success is the "gurgle." If you used to hear a splashing sound behind the dashboard when you started the car, that should be gone now. That sound was literally air bubbles moving through your heater core. No more gurgle means you're good to go.
Final thoughts on the L90 cooling system
The L90 is a tough car, but it's sensitive to its cooling. Keeping a عکس پیچ هواگیری ال 90 handy or at least knowing exactly where that little screw is can save you from a breakdown on the side of the road. It's one of those "five-minute fixes" that prevents a "five-hundred-dollar problem."
Just remember: be patient, let the engine cool down, and treat those plastic caps like they're made of glass. If you do that, your L90 will probably keep running until the odometer hits numbers you didn't think were possible. It's all about the small maintenance tasks, and bleeding the air is near the top of that list. Next time you're under the hood, just take a second to find it so you know exactly where it is for the day you actually need it. Safe driving!